Custom Vibration Isolation & Acoustic-Control Parts for Power Equipment
H-O Products die-cuts and converts load-bearing elastomer pads, cork-rubber, vinyl-nitrile, EPDM and silicone foam, constrained-layer damping patches, and acoustic-absorption and sound-barrier layers into the isolation pads, anti-vibration washers, and enclosure treatments that steady transformers, reactors, gensets, battery-storage HVAC, and wind and hydro auxiliaries, built to your drawing.
Built for: load-bearing isolation pads under transformers, reactors, and generator skids; anti-vibration washers and gaskets for control panels; constrained-layer damping on cabinet panels; and acoustic-absorption foam and limp-mass barriers inside genset canopies, BESS enclosures, and substation control houses, on your footprint drawing.
To control vibration and noise on power equipment, decide which of four jobs you have. Isolation: a load-bearing pad of rebonded neoprene, cork-rubber, ribbed neoprene, or EPDM between the skid and the foundation, sized so its natural frequency sits well below the forcing frequency — isolation only occurs above a forcing-to-natural ratio of √2, and a pad tuned too stiff amplifies.
Damping: a constrained-layer viscoelastic patch on a ringing cabinet panel. Absorption: open-cell polyether or reticulated PU lining in a genset canopy or BESS enclosure. Barrier: a limp-mass silicone sound-barrier layer. All four are mapped with methods in the When-to-spec list. Values are per the TDS on file; see the material reference below for ordering details.
Material-level, per the maker TDS: ASTM D3574 (flexible cellular urethane, CFD and compression set) · ASTM D1056 (cellular-rubber classification) · ASTM D2240 (durometer) · ASTM D575 (rubber in compression) · ASTM E756 (vibration-damping loss factor) · ASTM C423 (reverberation-room sound absorption, NRC) · ASTM E1050 (impedance-tube normal-incidence absorption) · UL 94 (flammability classes incl.
V-0 on the rated grades). Assembly-level, by designation (the level belongs to the installed asset or enclosure): IEC 60076-10 (transformer sound-level determination) · NEMA TR 1 (transformer sound levels) · the local noise ordinance (property-line dBA).
Isolation theory (natural frequency, the √2 crossover, transmissibility, creep) cited to named engineering references.
- Transformer / reactor base pad: rebonded neoprene / cork-rubber
- Generator skid isolation: rebonded neoprene + H-O mount
- Outdoor / UV isolation seal: EPDM foam / solid EPDM
- Oil / weather pad: neoprene / vinyl-nitrile
- Precision panel washer: PORON® 4701
- Hot / flame-rated isolation: silicone foam (BISCO® HT)
- Cabinet-panel damping: constrained-layer viscoelastic
- Enclosure absorption: open-cell PU / reticulated PU
- Transmission barrier: silicone sound-barrier
- Indoor / economical pad: natural rubber (not outdoors)
This guide is for acoustic, mechanical, and plant engineers specifying load-bearing isolation pads, anti-vibration washers, constrained-layer damping patches, and acoustic-absorption or sound-barrier layers for transformers, reactors, generator skids, battery-energy-storage enclosures, wind-turbine nacelle auxiliaries, and hydro and pump-station equipment, and for the sourcing buyers qualifying those made-to-order parts.
If you own a transformer hum walking into a control house, a genset transmitting into a slab, a BESS fan complaint at a property line, or a control cabinet that rings, start here.
For OEM switchgear and relay internals, see the electromechanical vibration and shock sibling; for consumer-device fans and speakers, see the electronics vibration and acoustic sibling.
Noise or vibration problem → isolate-damp-absorb-or-barrier decision → material selection → converted part → production supply.
- 1Name the sourceTransformer or reactor (line frequency), generator skid (RPM / firing order), BESS or canopy fan, or a ringing cabinet panel, with its dominant frequency.
- 2Isolate, damp, absorb, or barrierDecide the physics: decouple the mass, dissipate the panel ring, absorb the reverberant noise, or block the transmission path with a limp mass.
- 3Size for load and frequencySet the pad's natural frequency below the forcing frequency, and keep its sustained bearing stress inside the working range so creep does not expire the spec.
- 4Select the material familyMatch the outdoor environment (UV, ozone, oil), temperature, and flame class to cork-rubber, rebonded neoprene, EPDM, silicone, or an absorption foam.
- 5Die-cut to drawingAdd adhesive, liner, laminations, and washer geometry; die-cut, kiss-cut, waterjet, or kit the pad, washer, patch, or panel.
- 6Quote prototype or productionSend the drawing and volumes; review comes back with a manufacturable option and the TDS.
Where are you in the spec process?
This page serves engineers who already know the pad, washer, patch, or foam they want and engineers still deciding whether the problem is isolation, damping, absorption, or a barrier. Pick the path that matches where you are.
Send a drawing, get a quote
A rebonded-neoprene base pad, a cork-rubber isolation pad, an EPDM washer, a constrained-layer damping patch, or an absorption or sound-barrier panel on your drawing.
Skip to the quote form →Decide the physics, then the material
Six selection factors (isolate vs damp vs absorb vs barrier, natural frequency, sustained load and creep, outdoor environment, panel treatment), a checklist-driven part builder, and eleven material families with TDS-cited data.
Start with selection factors →
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1Send drawingUpload a DXF, STEP, or PDF, or describe the transformer, skid, enclosure, or panel. A sample part works too.
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2Material reviewEngineering reviews the isolation, damping, absorption, or barrier job against the maker TDSs, sizes the pad by natural frequency and sustained load, and frames the standards language honestly: material classes (UL 94, ASTM) by TDS; transformer sound and community limits by designation.
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3PrototypeSamples typically ship in 3–5 business days for common configurations on materials we keep on hand. Made-to-order; MOQ varies by material and part.
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4ProductionStandard production runs ship about 2 weeks after drawing approval, on flatbed die-cutting, waterjet cutting for thick pads, and kitting for laminated damping and barrier stacks. Ongoing parts run with material traceability and lot-code TDS records.
Which equipment are you quieting?
Application Zones
Six material problems define vibration and acoustic control on energy-infrastructure equipment: isolating a transformer or reactor from its foundation; isolating a generator skid from the slab; managing battery-storage HVAC and fan noise inside an enclosure; steadying the auxiliaries in a wind-turbine nacelle; isolating hydro and pump-station equipment; and damping and absorbing noise in a substation control house and its cabinets. Click a tab to see the part, the controlling property, and the families H-O converts for that zone.
Tip: the transformer tone is fixed by the grid (100 or 120 Hz); you cannot move it, so you move the pad, tuning its natural frequency far below the tone.
Transformer & reactor isolation: carry the mass, blunt the 100/120 Hz hum
A power transformer or reactor hums continuously because magnetostriction makes its core laminations change dimension twice per electrical cycle, so the tone sits at twice line frequency, 100 Hz on a 50 Hz grid and 120 Hz on a 60 Hz grid, with harmonics above it. That is a low-frequency, structure-borne problem, so the pad under the base is doing two jobs at once: it carries a multi-ton static load, and it decouples the hum from the foundation before it walks into a nearby control house.
The engineering is tuning plus load, not thickness: the pad is a spring whose natural frequency follows from its static deflection under the mounted mass, and isolation only begins once the forcing tone is above √2 times that natural frequency. Load-bearing families do this work: rebonded neoprene (the 25#/27# densities; the H-O 27# grade reports 14 psi compression deflection per ASTM D1056 on its data sheet) and cork-rubber composite, whose closed cork cells give a high loss factor and low creep.
The declared sound level belongs to the transformer and its evaluation per IEC 60076-10; the pad supports the acoustic design and never carries the rating.
Generator skid isolation: keep the firing order out of the slab
An engine-generator skid is a heavy rotating machine with a firing order and an imbalance, and bolting it hard to the slab pushes those tones straight into the building and the switchgear room. Base isolation under the skid is a static-stress calculation first: size the pad so its bearing stress sits inside its working range, then confirm the natural frequency lands below the skid's dominant frequency.
Rebonded neoprene carries the heavier skid loads; molded or ribbed mounts (coordinated through the partner network for molded geometries) handle point-support duty; and vinyl-nitrile or neoprene covers the lighter auxiliary skids and day-tank supports. Because the room smells of diesel, the enclosure gaskets around the same equipment often want an oil-resistant chemistry, which is where fluorosilicone and nitrile-based foams earn their place.
The acoustic side of the same canopy, absorption and barrier, is the BESS and enclosure zone.
BESS & enclosure acoustics: fan isolation, absorption, and barrier
A battery-energy-storage enclosure is quiet electrically and loud mechanically: its noise comes from HVAC, cooling fans, condensing units, and inverters, and the number that matters is the dBA at the property line, set by the local ordinance and usually stricter at night. Three different parts answer three parts of that problem. Isolation pads and washers under the fans and HVAC units decouple their tones from the enclosure skin.
Open-cell absorption foam, polyether PU or reticulated PU, lines the interior to cut the reverberant build-up that makes an enclosure louder than its sources. And where transmission through a panel is the leak, a limp-mass silicone sound-barrier layer adds the area density that blocks it. The same trio treats a genset canopy. Absorption is characterized by a sound-absorption coefficient measured per ASTM C423 or ASTM E1050; the barrier by its area density.
The property-line result belongs to the installed enclosure, not to any single layer.
Wind-turbine nacelle auxiliaries: steady the small machines up-tower
The rotor and drivetrain of a wind turbine are engineered up-tower, but a nacelle is also full of small auxiliaries, cooling fans, hydraulic and lubrication pumps, converter cabinets, and control panels, and each is a vibration or noise source that couples into the nacelle structure and the tower. The parts are the same isolation, damping, and washer parts as at grade, chosen for the nacelle's temperature range and its long, hard-to-service life.
PORON® microcellular urethane supplies precision low-load isolation and washers with the low compression set that keeps the tuning alive; silicone foam covers the hotter converter and brake-resistor areas and any flame-class requirement; and constrained-layer damping patches quiet the thin converter-cabinet and cover panels. Because service means a crane, the premium here is on materials whose compression set and creep keep the part doing its job for years without a visit.
Hydro & pump-station equipment: isolate the rotating machinery
Hydro plants and water and wastewater pump stations run rotating machinery, pumps, motors, and small generators, in damp, sometimes wet environments where the isolation pad has to keep working through humidity and splash.
The isolation logic is the same static-stress-then-natural-frequency calculation, and the material choice leans on the closed-cell and weather-resistant families: rebonded neoprene and neoprene foam for the load-bearing pads, EPDM where standing water and ozone are the concern, and cork-rubber where a high loss factor is wanted under continuous rotation.
Solid rubber pads and washers take the tolerance-take-up and mounting duty. As always, the pad is sized so its sustained bearing stress stays inside its working range, because a pump that runs continuously for years will find any pad that was loaded past its creep limit.
Substation control house & panels: damp the ring, absorb the room
Inside a substation control house the vibration and noise are subtler: thin control-cabinet and relay-panel sheet metal rings when nearby equipment excites it, and the room itself builds up reverberant noise from transformers, HVAC, and the gear. Two treatments answer them. Constrained-layer damping patches, a viscoelastic core laminated between the panel and a stiff skin so the layer works in shear, cut the panel ring; ASTM E756 formalizes the loss-factor measurement, and a loss factor of about 0.1 is generally the threshold for meaningful damping.
Absorption foam on the walls and inside cabinets cuts the reverberant build-up, characterized by a sound-absorption coefficient per ASTM C423 or E1050. Anti-vibration washers under bolted panel feet and equipment take the last of the structure-borne path. None of these parts carries a room sound rating; they are the converter-side layers of an acoustic design.
Six decisions that drive your isolation & acoustic material spec
A power-equipment vibration or acoustic part is a single-purpose layer, and each has one controlling property. Miss it and the failure is quiet: a pad amplifies instead of isolates, a pad creeps and the standoff expires, a foam absorbs when the job was to block, or an outdoor elastomer cracks in the sun.
Isolation, damping, absorption, and barrier are four different physics. Isolation decouples a mass with a compliant element and only works above a frequency ratio of √2 relative to the pad's natural frequency. Damping dissipates energy as heat and cuts the resonant peak of a ringing panel. Absorption cuts reverberant build-up inside an enclosure. A barrier blocks transmission with limp mass. The transformer tone at 100/120 Hz is low-frequency, so it is an isolation and mass problem first. Decide which job you have; the material follows.
Below a forcing-to-natural frequency ratio of √2 (≈1.414), an isolator amplifies. A common rule of thumb sizes the mount so its natural frequency is about one third of the frequency of concern, which puts the source comfortably in the isolation region. The natural frequency follows from the static deflection under the mounted load (fn ≈ 3.13√(K/W), or the deflection form fn = (1/2π)√(g/δ)), so the load and the pad's stiffness, not its gauge, set the tuning. [9]
Read the six factors below in order. The first two decide the physics and the tuning; the next two size the pad for sustained load and pick the outdoor material; the last two cover enclosure noise and the panel and washer parts. Every factor names its test method, because in this application the documentation is part of the part.
Show all 6 selection factors tap to expand
Decide the job: isolate, damp, absorb, or barrier
Rule — name the physics before the material. Isolation decouples a source (transformer, skid, fan) from the structure with a compliant load-bearing element; damping dissipates a panel's resonant energy as heat; absorption cuts reverberant build-up inside an enclosure; a barrier blocks transmission with limp mass.
A base pad and an absorption foam solve different problems, and the wrong one quietly fails: an absorption foam does nothing for structure-borne hum, and an isolation pad does not quiet a reverberant room. State which of the four jobs the part does, then read the factor that matches. [9]
Tune the isolator by natural frequency, not thickness
Rule — size the pad so its natural frequency sits well below the forcing frequency. The pad is a spring; its natural frequency follows from the static deflection under the mounted mass (fn ≈ 3.13√(K/W), or the deflection form fn = (1/2π)√(g/δ)). Isolation begins only above a frequency ratio of √2, so a pad tuned too stiff lands in the amplification region and makes the vibration worse, exactly the trap at the transformer's 100/120 Hz tone.
Get the mounted mass, the bearing area, and the forcing frequency (line frequency, genset RPM, or fan tone) onto the drawing; the stiffness grade and thickness fall out of those. [9]
Size for sustained load: limit creep so the spec survives
Rule — a multi-ton machine sits on its pad for decades, so creep is a first-class spec input. An elastomer under sustained static load keeps deflecting slowly over time (creep, roughly with the logarithm of load time), and a pad loaded past its working range drifts until the isolation standoff and the tuning are gone.
Keep the sustained bearing stress inside the pad's published working range: a common bearing-pad practice keeps strain modest (on the order of 8–10%) with a compressive-stress limit (about 1500 psi for consistent long-term performance), taking a working figure near 30% creep of the initial deflection.
Cork-rubber and high-density rebonded neoprene resist creep; soft foams drift if overloaded. Send the mass and bearing area so the pad is sized to its load, not just its footprint. [8]
Pick the elastomer for the outdoor environment
Rule — most of this equipment lives outdoors, so weathering decides the family. EPDM has the standout ozone, UV, and weather resistance and is the outdoor default for isolation-plus-sealing; neoprene (polychloroprene) brings good general weather and oil resistance; silicone covers the widest temperature range and holds up to UV and ozone. Natural rubber is economical but has poor ozone and UV resistance, so it cracks and hardens in prolonged sun and is kept for indoor or protected duty.
Cork-rubber adds load-bearing damping with low creep. Name the exposure (UV, ozone, oil, standing water) and the temperature range; those route you to the family before cost does. [15]
Enclosure noise: absorb the reverberation, barrier the transmission
Rule — they are opposite jobs, so specify them separately. Absorption cuts the reverberant build-up inside a genset canopy, BESS enclosure, or control house with open-cell PU or reticulated PU foam, characterized by a sound-absorption coefficient per ASTM C423 (reverberation room, NRC) or ASTM E1050 (impedance tube). A barrier blocks transmission through a panel with a limp-mass layer, sold by area density.
Absorption foam alone will not stop a leak through a panel, and a barrier alone will not calm a live room. And a thin absorber does little for the transformer's low-frequency tone, which is an isolation and mass problem. Call out the absorption target and the transmission-loss need separately, plus any flame class; the enclosure's dBA belongs to the installed asset.
Panel damping & anti-vibration washers: the last of the path
Rule — match the fix to the mechanism. A ringing control-cabinet or converter panel wants a constrained-layer damping patch (a viscoelastic core in shear between the panel and a stiff skin), where a loss factor of about 0.1 is generally the threshold for meaningful damping per ASTM E756. A bolted joint that transmits structure-borne vibration wants an anti-vibration washer or gasket, a PORON® or elastomer part whose low compression set holds the standoff.
Felt and cork shims decouple squeaking or tolerance-take-up joints. Tell us the panel material and thickness and where the bolted joints are; the patch or washer follows. [7]
Specification Tools
Two tools to take you from "we have a vibration or noise problem" to here is the material checklist for the drawing set: a requirement-driven part builder that assembles the layer list with its citations, and a side-by-side comparison of every family on this page.
1. Power-equipment vibration & acoustic part checklist builder
Check the problems your equipment has. The builder assembles the corresponding parts into a checklist with the family, what to send with the drawing, and the honest citation language (material classes per TDS; isolation theory by reference; transformer sound and community limits by designation). The default selection is a typical outdoor transformer with a control-house acoustic problem; every part is also printed in the material reference section, so nothing here exists only behind a script.
Part checklist: 4 parts selected
Each checked problem adds its part below. The list is the starting bill of materials for the engineering review, not a certification: material classes (UL 94, ASTM) come from the grade TDS, isolation tuning follows the cited theory, and the declared transformer sound and property-line noise belong to the installed asset.
- Transformer / reactor base pad: rebonded neoprene or cork-rubberSend: equipment mass, bearing area, forcing frequency (line freq). Cite: class per ASTM D1056; tune below √2 crossover; size for sustained load.
- Outdoor pad / washer: EPDM (UV / ozone)Send: exposure (UV, ozone, standing water), temperature. Cite: EPDM weathering resistance; class per ASTM D1056.
- Enclosure absorption foam: open-cell / reticulated PUSend: interior area, airflow, flame-class need. Cite: absorption coefficient per ASTM C423 / E1050.
- Panel damping: constrained-layer viscoelastic patchSend: panel material, thickness, resonant band. Cite: loss factor per ASTM E756 (η ≥ 0.1 target).
2. Side-by-side: material family comparison matrix
Every family called out on this page, with construction, the property that drives its selection, the methods its TDS cites, and the job it serves. Click a column header to sort. Click any material name to jump to its accordion entry.
| Material | Construction | Selection driver | Methods on the TDS | Job | |
|---|---|---|---|---|---|
| Load-bearing isolation | |||||
| Rebonded Neoprene (25# / 27#)High-density rebond | Dense rebonded foam | Static stress + low creep | ASTM D1056 (14 psi, 27#) | Transformer / genset pads | |
| Cork & Rubberized CorkCork-rubber composite | Cork + rubber composite | Load-bearing + high loss factor | Load-deflection per TDS | Machinery base pads | |
| Neoprene Foam & SolidPolychloroprene | Closed-cell / solid neoprene | Weather + oil resistance | ASTM D1056; D2240 | Ribbed / waffle pads | |
| EPDM Foam & SolidEPDM | Closed-cell / solid EPDM | Ozone / UV / weather | ASTM D1056; D2240 | Outdoor isolation + seal | |
| Vinyl-Nitrile Foam (Ensolite®)PVC/NBR closed-cell | Closed-cell PVC/NBR foam | Cost + oil resistance | ASTM D1056 | Aux skid / anti-rattle | |
| PORON® Industrial (4701 Series)Microcellular urethane | Microcellular PU foam | CFD window + low set | ASTM D3574; D2240 | Precision washers / aux | |
| Silicone Foam (BISCO® HT)Closed-cell silicone | Closed-cell silicone foam | Temp range + flame class | UL 94 V-0; -55/+200 C (TDS) | Hot isolation / seal | |
| Absorption, barrier & damping | |||||
| Open-Cell / Reticulated PU FoamAbsorption foam | Open-cell / reticulated PU | Absorption coefficient (NRC) | ASTM C423; E1050 | Enclosure lining | |
| Silicone Sound Barrier (BISCO® A2)Limp-mass VMQ | Solid silicone mass layer | Area density (limp mass) | 1.2-8.2 kg/m² (TDS) | Transmission barrier | |
| Viscoelastic Damping (CLD)CLD patch | Viscoelastic + skin laminate | Loss factor (η ≥ 0.1) | ASTM E756 | Panel / cabinet damping | |
| Natural Rubber (foam / solid)NR (indoor only) | Natural-rubber foam / solid | Economical (poor UV/ozone) | ASTM D1056; D2240 | Indoor / protected pads | |
Skip ahead and request your engineering review now
If your drawing set already calls out a rebonded-neoprene pad, a cork-rubber isolator, an EPDM washer, a damping patch, or an absorption or barrier layer, send it over for engineering review against the TDSs and the isolation tuning.
Power-equipment vibration & acoustic failures you can prevent at spec
These parts fail quietly: a pad tuned into amplification, a pad that crept until the standoff was gone, an outdoor elastomer that cracked in the sun, a foam that absorbed when the job was to block, a panel nobody damped. Five patterns cover most of it, and each is a specification decision made before the first part is cut.
An isolator you did not tune can amplify. The most common mistake on this page is treating a base pad as a spacer and selecting it by thickness. If its natural frequency lands within √2 of the forcing frequency, transmissibility rises above 1 and the pad makes the vibration worse, and at the transformer's 100/120 Hz tone that is easy to do. Tune by natural frequency; state the mounted mass and forcing frequency.
Show all 5 failure modes tap to expand
1. The base pad that amplified instead of isolating
Fix — tune by natural frequency, not gauge, and keep the forcing tone above the √2 crossover. A transformer or skid pad was chosen for standoff: the right thickness, the wrong spring. Its natural frequency landed near the equipment's dominant frequency, transmissibility climbed above 1, and the "isolator" pushed more vibration into the slab and the control house. Isolation only occurs above a forcing-to-natural frequency ratio of √2, and a common rule sizes the pad's natural frequency at about a third of the frequency of concern.
Get the mounted mass, the bearing area, and the forcing frequency (line frequency for the transformer, RPM for the skid) onto the drawing, and let the stiffness grade and thickness fall out of the tuning. [9]
2. The pad that crept until the standoff was gone
Fix — size for sustained load, not just footprint, and keep the bearing stress in the working range. A pad under a multi-ton transformer was sized to fit the base, not to carry the load, so it was overstressed and kept deflecting slowly (creep) until the standoff collapsed and the tuning drifted. Elastomers creep under sustained static load roughly with the logarithm of time, and a pad loaded past its working range never stops.
Keep the strain modest (on the order of 8–10%) and the compressive stress inside the pad's published limit (about 1500 psi for consistent long-term performance), take a working figure near 30% creep of the initial deflection, and reach for cork-rubber or high-density rebonded neoprene where creep resistance matters. Send the mass and bearing area with the drawing. [8]
3. The outdoor elastomer that cracked in the sun
Fix — pick the elastomer for the exposure; natural rubber is an indoor material. A pad or washer chosen for economy was natural rubber, and on an outdoor transformer or pad-mount unit it hardened and cracked under ozone and UV within a couple of seasons, so it stopped isolating and started leaking. EPDM is the outdoor default for its ozone, UV, and weather resistance; neoprene brings good weather and oil resistance; silicone covers the widest temperature range with good UV and ozone resistance.
Name the exposure (UV, ozone, oil, standing water) and the temperature range on the drawing, and keep natural rubber for indoor or protected duty. [15]
4. The absorption foam that could not block a leak (or the barrier that could not calm a room)
Fix — absorption and barrier are opposite jobs; specify the one the noise needs. An enclosure was lined with open-cell absorption foam to fix a transmission leak through a panel, and the dBA at the fence barely moved, because absorption cuts reverberant build-up, not transmission. The reverse also happens: a limp-mass barrier is added to a live room that actually needed absorption.
Use open-cell PU or reticulated PU (absorption coefficient per ASTM C423 / E1050) to calm a reverberant enclosure, and a limp-mass silicone sound-barrier layer (sized by area density) to block a panel path. And remember the transformer's 100/120 Hz tone is low-frequency: thin foam does little for it, so that one is an isolation and mass problem. [6]
5. The control-cabinet panel nobody damped
Fix — damp the ringing panel with a constrained-layer patch, and hold bolted joints with anti-vibration washers. A relay or converter cabinet's thin sheet-metal panels rang when nearby equipment excited them, buzzing at their resonances, and no isolation pad fixed it because the problem was panel resonance, not a decoupled mass.
The fix is a constrained-layer damping patch, a viscoelastic core in shear between the panel and a stiff skin, which dissipates the resonant energy as heat; ASTM E756 reports the loss factor, and about 0.1 is generally the threshold for meaningful damping.
Bolted panel and equipment feet that transmit structure-borne vibration get an anti-vibration washer whose low compression set holds the standoff. Send the panel material, thickness, and resonant band. [7]
Material reference
Detailed specs for the eleven families referenced on this page: the load-bearing isolation materials (rebonded neoprene, cork-rubber, neoprene, EPDM, vinyl-nitrile, PORON®, and silicone foam), the acoustic materials (open-cell and reticulated PU absorption foam and the limp-mass silicone sound barrier), the damping construction, and the indoor natural-rubber option.
Values are per the maker TDS on file for each grade with the method named; isolation theory and community-noise context are cited by reference and by designation. H-O die-cuts, kiss-cuts, slits, waterjet-cuts, and kits every family to drawing.
Rebonded Neoprene (25# / 27# Density)Transformer & genset base pads · ASTM D1056 · load-bearing, low creep
Size a base pad by static bearing stress (mass over pad area), then confirm the natural frequency lands below the forcing frequency. Values per the H-O 27# rebonded neoprene TDS on file (ASTM D1056-07).
Cork & Rubberized Cork (Cork-Rubber Composite)Machinery isolation pads · high loss factor · low creep
Cork-rubber is a load-bearing damping material, not a soft spring; size it to its published load-deflection range. Values per the cork-rubber maker TDS on file.
Neoprene Foam & Solid (Polychloroprene)Ribbed / waffle pads & washers · good weather & oil resistance · ASTM D1056
Neoprene brings good weather, ozone, and oil resistance; for the harshest UV and ozone exposure step up to EPDM. Class per ASTM D1056 on the grade TDS.
EPDM Foam & SolidOutdoor isolation + sealing · excellent ozone / UV / weather · ASTM D1056
EPDM is the outdoor default for its ozone and UV resistance; it is not the oil-resistant choice, so name any hydrocarbon exposure. Class per ASTM D1056 on the grade TDS.
Vinyl-Nitrile & PVC-Nitrile Foam (Ensolite® family)Cost-effective isolation & anti-rattle · closed-cell · oil resistant
Cite the specific grade: density, temperature, and class vary across the Ensolite® family. Values per the individual grade TDS on file.
PORON® Industrial Microcellular Urethane (4701 Series)Precision anti-vibration washers & aux isolation · ASTM D3574 · low compression set
Specify the CFD window (kPa) and a compression-set limit at the service temperature, plus the mounted mass, not just thickness. Values per the Rogers PORON® 4701 very-firm-grade TDS (Publication #17-018) on file.
Silicone Foam (BISCO® HT Series, Medium Grade)Hot / flame-rated isolation & seals · -55 to +200 °C · UL 94 V-0 per TDS
Match the compression class to the real closure force, and let any flame-class requirement pick the silicone track before cost does. UL 94 classes are per the individual grade TDS; H-O cites them by designation and does not certify the class.
Open-Cell & Reticulated PU Absorption FoamEnclosure lining · sound-absorption coefficient · ASTM C423 / E1050
Absorption cuts reverberant build-up; it does not block transmission (that is the barrier). The transformer's low-frequency tone needs isolation and mass, not a thin absorber. Values per the maker TDS with the method named.
Silicone Sound Barrier (BISCO® A2)Limp-mass transmission barrier · area density 1.2–8.2 kg/m² · per TDS
A barrier blocks transmission by mass; it does not absorb. Specify the area density and the transmission-loss need. Values per the Rogers BISCO® A2 sound-barrier TDS (Pub #180-251) on file.
Viscoelastic Constrained-Layer Damping (CLD)Cabinet-panel damping patch · loss factor · ASTM E756
Damping is not isolation: a patch cuts a panel's ring, it does not decouple a mass. Provide the panel material, thickness, and resonant band; loss factor per ASTM E756. The tape validation framing applies for adhesive selection: confirm the substrate, surface energy, temperature, exposure, dwell, pressure, prep, geometry, and assembly.
Natural Rubber (Foam & Solid)Economical indoor / protected pads · poor ozone / UV · ASTM D1056 / D2240
Natural rubber is economical and resilient but not weather-durable: keep it indoors or protected, and step up to EPDM or neoprene for any outdoor exposure. Class per ASTM D1056 on the grade TDS.
Fluorosilicone (FVMQ) Sponge (Fuel & Chemical Resistant)Fuel / solvent splash seals with silicone cold flexibility · ~ -60 to +200 °C
Specify fluorosilicone by naming the fuel or solvent and the temperature; compatibility is read from the maker TDS and ASTM D471 immersion data, never assumed. Where chemical aggressiveness outranks cold flexibility, step to FKM.
Power-equipment vibration & acoustic materials: engineer-grade FAQ
Twelve of the questions we hear most from acoustic, mechanical, and plant teams working on transformers, gensets, battery storage, and substation equipment. If your question isn't here, send a drawing or call, engineering picks up.
Why does a transformer hum, and at what frequency?
Because of magnetostriction: the transformer's core laminations physically change dimension as the magnetic field cycles, and because the field magnitude peaks twice per electrical cycle regardless of polarity, the hum sits at twice the line frequency, about 100 Hz on a 50 Hz grid and 120 Hz on a 60 Hz grid, with audible harmonics above it. That is a low-frequency, structure-borne tone, which is why it is primarily an isolation and mass problem rather than a job for thin absorption foam.
The declared sound level of the transformer is determined per IEC 60076-10; the pad supports the acoustic design and never carries the rating. [1]
Can an isolation pad make the vibration worse instead of better?
Yes, and it is the most common mistake on this page. Isolation only occurs above a forcing-to-natural frequency ratio of √2 (about 1.414). If the pad's natural frequency is too close to the forcing frequency, the system runs in the amplification region, where transmissibility rises above 1 and the pad transmits more than it blocks, worst at resonance where the ratio is 1. The fix is to tune the pad so its natural frequency sits well below the forcing tone, often around a third of it.
The natural frequency follows from the static deflection under the mounted load, so the mounted mass and the pad's stiffness set the tuning, not the thickness. [9]
How do I size an isolation pad for a transformer or generator skid?
It is a static-stress calculation first, then a frequency check. Size the pad so its bearing stress (the equipment mass over the pad area) sits inside the pad's working range, so it does not bottom out or creep excessively. Then confirm the natural frequency at that load lands below the forcing frequency (line frequency for a transformer, RPM or firing order for a genset), keeping the forcing tone above the √2 crossover.
Send the equipment mass, the number and area of the pads, and the forcing frequency, and the family and thickness fall out of those. Rebonded neoprene and cork-rubber carry the heavier loads with low creep. [13]
What is creep, and why does it matter for a pad under a transformer?
Creep is the slow, continued deflection of an elastomer held under sustained static load, and it increases roughly with the logarithm of load time. A pad under a multi-ton transformer sits loaded for decades, so a pad sized only to fit the footprint (not to carry the load) keeps sinking until the isolation standoff and the tuning are gone.
The prevention is to keep the sustained bearing stress inside the pad's working range: a common bearing-pad practice keeps strain modest (on the order of 8–10%) with a compressive-stress limit (about 1500 psi for consistent long-term performance) and treats about 30% creep of the initial deflection as a working figure.
Cork-rubber and high-density rebonded neoprene resist creep best. [8]
Which elastomer should I use for an outdoor transformer or substation pad?
Pick for the exposure. EPDM has the standout ozone, UV, and weather resistance and is the outdoor default for isolation combined with sealing. Neoprene (polychloroprene) brings good general weather and oil resistance where a hydrocarbon exposure is present. Silicone covers the widest temperature range with good UV and ozone resistance for the hottest or coldest spots. Natural rubber is economical but has poor ozone and UV resistance, so it cracks and hardens in prolonged sun and belongs indoors or in a protected location, not on an outdoor transformer.
Cork-rubber adds load-bearing damping with low creep. Name the exposure and temperature range on the drawing. [15]
What is the difference between isolation, damping, absorption, and a barrier?
Four different physics for four different jobs. Isolation decouples a source (transformer, skid, fan) from the structure with a compliant load-bearing element, specified by natural frequency. Damping dissipates a panel's resonant energy as heat, specified by loss factor, and cuts the ring of a ringing panel. Absorption cuts reverberant build-up inside an enclosure, specified by a sound-absorption coefficient. A barrier blocks transmission through a panel with a limp mass, specified by area density.
The transformer's low-frequency hum is an isolation and mass problem; a ringing cabinet panel is a damping problem; a reverberant BESS enclosure is an absorption problem; a leaking panel is a barrier problem. [9]
What lines a generator canopy or a BESS enclosure to cut noise?
A combination, because the noise has more than one path. Open-cell polyether PU or reticulated PU absorption foam on the interior cuts the reverberant build-up that makes an enclosure louder than its sources, characterized by a sound-absorption coefficient per ASTM C423 or E1050; reticulated grades let cooling air pass. Where sound leaks through a panel, a limp-mass silicone sound-barrier layer adds the area density that blocks transmission, and the two are often laminated into one stack.
Isolation pads under the fans and HVAC units decouple their tones from the skin. In a BESS the noise is mostly HVAC, fans, and inverters, and the number that matters is the dBA at the property line, set by the local ordinance. [6]
Do these parts carry an IEC 60076-10 sound level or an ordinance rating?
No, and no honest supplier will claim otherwise. A transformer's declared sound level is determined by testing the transformer per IEC 60076-10 (with NEMA TR 1 tabulating levels by rating), and the community-noise limit is the dBA at the property line, set by the local ordinance and often stricter at night. Both belong to the installed asset and its enclosure, not to a pad or foam.
What the materials carry is their own documentation: material-level classes like UL 94 on the rated grades, the ASTM methods behind their properties, and lot-code traceability. They support the acoustic design; H-O supplies the converted layers and the paperwork, and the asset owner and acoustician own the system result. [2]
Cork-rubber, neoprene, or rebonded neoprene: which base pad do I pick?
By load and duty. Rebonded neoprene is the high-density load-bearing choice under the heaviest transformers and skids, sized by static bearing stress with low creep (the H-O 27# grade reports 14 psi compression deflection per ASTM D1056). Cork-rubber is the classic machinery mount where a high loss factor is wanted alongside load-bearing, damping the hum with low creep. Ribbed or waffle neoprene covers lighter feet with good weather and oil resistance.
All three are sized to carry the load first, then checked so the natural frequency lands below the forcing frequency. Send the mass and bearing area, and the choice follows the load. [14]
How do I quiet a ringing control-cabinet or converter panel?
Damp it, do not try to isolate it. A thin sheet-metal panel rings at its resonances when nearby equipment excites it, and an isolation pad does nothing for that because the problem is panel resonance, not a decoupled mass. The fix is a constrained-layer damping patch: a viscoelastic core laminated between the panel and a stiff constraining skin, so the core works in shear and dissipates the resonant energy as heat.
ASTM E756 reports the loss factor, and a loss factor of about 0.1 is generally the threshold for meaningful damping. For a bolted joint that transmits vibration, add an anti-vibration washer whose low compression set holds the standoff. Provide the panel material, thickness, and resonant band. [7]
Does H-O mold isolation mounts, or convert them?
H-O and converts sheet, roll, and slab stock to drawing: die-cut, kiss-cut, waterjet-cut, slit, laminated, and kitted pads, washers, strips, and damping and barrier stacks. That covers the great majority of the isolation, damping, absorption, and barrier parts on this page. Molded isolation mounts and extruded profiles are coordinated through a partner network, since H-O does not perform molding or profile extrusion in-house.
Conversion runs in Winsted, Connecticut under an ISO 9001:2015 certified quality management system with material traceability and lot-code TDS records.
What should I send H-O to get a quote?
By job: for isolation, the equipment type and mass, the pad bearing area, and the forcing frequency (line frequency, genset RPM, or fan tone), plus the indoor/outdoor exposure and temperature; for damping, the panel material, thickness, and resonant band; for absorption, the enclosure interior area, the airflow, and any flame class; for a barrier, the panel area and the transmission-loss need.
Plus a footprint or panel drawing, adhesive and liner needs, and quantities for prototype and production. Any declared IEC 60076-10 sound level or local-ordinance dBA target is useful context, though H-O sizes the materials, not the system compliance result. "Recommend the part" is a valid callout, that is what the engineering review is for.
Glossary: terms used on this page
Quick reference for the vibration, damping, and acoustic terminology used throughout. Each entry links to the relevant reference or test method where applicable.
Magnetostriction (transformer hum)
The dimensional change of a ferromagnetic core as the magnetic field cycles, the source of transformer and reactor hum, per [1]. Because the field magnitude peaks twice per electrical cycle, the tone sits at twice line frequency (100 Hz at 50 Hz, 120 Hz at 60 Hz) plus harmonics.
Vibration isolation
Reducing the transmission of vibrational energy from one body to another by inserting a resilient (compliant) element, per [9]. A load-bearing pad decouples a transformer, skid, or fan from the structure. Isolation only occurs above a frequency ratio of √2 relative to the pad's natural frequency.
Damping
The dissipation of vibrational energy, usually as low-grade heat, which lowers a panel's resonant amplitude and stops it ringing. Different physics from isolation: damping removes energy; isolation redirects the transmission path. Measured as a loss factor per ASTM E756 [7].
Natural frequency (fn)
The frequency at which an isolator naturally oscillates: fn = 3.13√(K/W) in English units, or the static-deflection form fn = (1/2π)√(g/δ), for the undamped case, per [9]. The tuning target: keep the forcing frequency well above it.
√2 crossover
The frequency ratio (≈1.414) at which transmissibility returns to 1. Below it is the amplification region (transmissibility > 1); above it is the isolation region (transmissibility < 1), per [9].
Transmissibility
The dimensionless ratio of vibration transmitted through an isolator to vibration applied. It rises toward a peak at resonance for a lightly damped system; damping lowers that peak, per [9]. Below 1 means isolation; above 1 means amplification.
Creep (sustained-load drift)
The continued slow deflection of an elastomer under sustained static load, increasing roughly with the logarithm of load time, per [8]. A pad loaded past its working range keeps creeping until the isolation standoff is lost; keeping strain modest and stress inside the published limit bounds it.
Compression set
The permanent thickness a material loses after sustained compression and release, per ASTM D3574 [4] / ASTM D1056 [3]. Low set (PORON®, silicone foam, cork-rubber) keeps an isolation tuning or a seal's closure force alive over service life.
Loss factor (η)
A dimensionless measure of a material's or assembly's damping (energy dissipated per cycle relative to energy stored). A composite loss factor of about 0.1 is generally the threshold for meaningful damping; measured per ASTM E756 [7].
Sound-absorption coefficient / NRC
The fraction of incident sound energy a material absorbs rather than reflects. Measured per ASTM C423 [6] (reverberation room, from which NRC is the average at 250/500/1000/2000 Hz) or ASTM E1050 [5] (impedance tube, normal incidence). Absorption cuts reverberant build-up, not transmission.
Limp-mass barrier
A dense, flexible layer that blocks sound transmission by adding area density (mass per unit area) to a panel, per [12]. Specified by area density (kg/m²). A barrier blocks transmission; it does not absorb reverberant noise (that is the absorption foam).
IEC 60076-10 (by designation)
Power transformers – Part 10: Determination of sound levels, per [2]. It defines how a transformer's or reactor's sound power and pressure are measured and declared. Cited here by designation: the declared level belongs to the tested transformer, and the materials support the acoustic design.
Last updated · Reviewed by H-O Products engineering (ISO 9001:2015 certified converter, Winsted, CT).
Standards, test methods & technical references
The standards, test methods, engineering references, and maker technical data sheets cited throughout this page. Transformer sound and community-noise limits are cited by designation and belong to the installed asset, not a part; isolation theory is cited to a named engineering reference. Standards editions current as of July 2026; verify against the publishing body before final spec. H-O materials are aligned to the standards cited through the source manufacturer's TDS, not independently certified by H-O unless explicitly stated on the quote.
[1] Magnetostriction / transformer hum (twice line frequency)
Forghani, B., "Magnetostriction, a Source of Noise in Transformers," Siemens Digital Industries Software (Simcenter). Explains that the transformer core hums at a fundamental of twice the power frequency (about 100 Hz at 50 Hz, 120 Hz at 60 Hz) due to magnetostriction of the laminations. blogs.sw.siemens.com (magnetostriction)
[2] IEC 60076-10 (by designation)
IEC 60076-10, "Power transformers – Part 10: Determination of sound levels" (Ed. 2.0:2016), with application guide IEC 60076-10-1. Defines the sound-pressure and sound-intensity methods for determining and declaring transformer, reactor, and cooling-auxiliary sound levels. Cited by designation; the level belongs to the tested transformer. webstore.iec.ch (IEC 60076-10)
[3-alt] NEMA TR 1 (transformer sound levels)
NEMA TR 1, "Transformers, Regulators and Reactors" (renumbered NEMA TP 80050), which tabulates audible sound levels for transformers by rating. Cited by designation as sound-level context for the installed asset. nema.org (NEMA TR 1 / TP 80050)
[3b] Community noise limits (local ordinance, by designation)
Community noise limits for substations and battery-storage sites are set by local ordinance (municipal or county), typically as a dBA limit at the property line and often stricter at night; battery-storage noise is driven mainly by HVAC, cooling fans, and inverters. Cited by designation as design context; the compliance result belongs to the installed asset and its enclosure. acentech.com (BESS noise control)
[5] ASTM E1050
ASTM E1050, "Standard Test Method for Impedance and Absorption of Acoustical Materials Using a Tube, Two Microphones and a Digital Frequency Analysis System." The impedance-tube method that yields the normal-incidence sound-absorption coefficient of an absorption foam. store.astm.org (ASTM E1050)
[6] ASTM C423
ASTM C423, "Standard Test Method for Sound Absorption and Sound Absorption Coefficients by the Reverberation Room Method." Yields the random-incidence absorption coefficient, from which NRC (average at 250/500/1000/2000 Hz) and SAA are computed. store.astm.org (ASTM C423)
[7] ASTM E756
ASTM E756, "Standard Test Method for Measuring Vibration-Damping Properties of Materials." Reports loss factor and modulus using cantilever (Oberst) and sandwich (constrained-layer) beam specimens; the method behind the damping-patch selection. A composite loss factor near 0.1 is a common threshold for meaningful damping. store.astm.org (ASTM E756)
[8] Creep of elastomeric bearing pads (Mason Industries)
Mason Industries, "Introduction" (bearing-pad design bulletin). Describes creep as additional deflection over time (a percentage of the initial deflection), a working figure near 30% creep, and a compressive-stress limit near 1500 psi with strain kept in the 8–10% range for consistent long-term performance. mason-ind.com (bearing pads)
[9] Basics of Vibration Isolation (E-A-R / Aearo)
Masterson, P. A., "The Basics of Vibration Isolation Using Elastomeric Materials," E-A-R Specialty Composites / Aearo Company. The named engineering reference for the √2 crossover, the natural-frequency forms (fn = 3.13√(K/W); fn = (1/2π)√(g/δ)), transmissibility, and the one-third rule of thumb cited on this page. vibrationdata.com (Basics of Vibration Isolation, PDF)
[10] Rogers BISCO® HT-series (medium) silicone foam TDS
Rogers Corporation BISCO® HT-series Medium Silicone Foam data sheet (Publication #180-070): -55 to +200 °C, density 352 kg/m³, CFD 67 kPa, compression set 2.4% (100 °C), UL 94 V-0 (File E83967), ASTM E162/E662, FMVSS 302. rogerscorp.com (BISCO silicones)
[11] Rogers PORON® 4701 very-firm-grade TDS
Rogers Corporation PORON® 4701 series very-firm-grade industrial microcellular polyurethane data sheet (Publication #17-018): CFD@25% 249/428/643 kPa (36/62/93 psi) across density sub-grades, compression set 10% or less at 70 °C; listed uses include vibration management and shock absorption. rogerscorp.com (PORON industrial 4701)
[12] Rogers BISCO® A2 sound-barrier TDS
Rogers Corporation BISCO® A2 Sound Barrier data sheet (Publication #180-251): a solid VMQ silicone limp-mass barrier used to block sound transmission, sold by area density 1.2–8.2 kg/m² (0.25–1.68 lb/ft²), density 1.64 g/cc, 62 Shore A, -50 to +180 °C. rogerscorp.com (BISCO A2 sound barrier)
[13] H-O Products 27# rebonded neoprene TDS
H-O Products 27# rebonded neoprene foam data: density 27.3 lb/ft³, compression deflection 14 psi (ASTM D1056-07), water absorption 1.8%; stated use includes heavy-duty vibration isolation and load-bearing support in industrial and heavy-machinery environments. h-oproducts.com (27# rebonded neoprene)
[14] Cork-rubber vibration isolation data
Amorim Cork Solutions, AcoustiCork "Vibration Isolation Solutions": engineered cork-and-rubber compounds with high loss factors that dissipate vibration into low-grade heat, with low amplification at resonance across a wide frequency range and low creep. The basis for the cork-rubber isolation-pad selection. amorimcorksolutions.com (cork-rubber isolation)
[15] Elastomer weathering selection (EPDM / neoprene / natural rubber / silicone)
Elastomer material-selection reference: EPDM's standout ozone, UV, and weather resistance; neoprene's good general weather and oil resistance; natural rubber's poor ozone and UV resistance; and silicone's wide service-temperature range. The basis for the outdoor-material selection on this page. robinsonrubber.com (elastomer selection)
[3] ASTM D1056 (cellular rubber)
ASTM D1056, "Standard Specification for Flexible Cellular Materials—Sponge or Expanded Rubber." The Type/Class/Grade classification behind the neoprene, EPDM, vinyl-nitrile, and rebonded cellular-rubber grades. store.astm.org (ASTM D1056)
[4] ASTM D3574 & D2240 / D575 (urethane and rubber methods)
ASTM D3574, "Standard Test Methods for Flexible Cellular Materials—Slab, Bonded, and Molded Urethane Foams" (CFD and compression set on the PORON® TDSs); with ASTM D2240 (durometer hardness) and ASTM D575 (rubber properties in compression) for the solid and foam grades. store.astm.org (ASTM D3574)
[16] ASTM D2240 (durometer)
ASTM D2240, "Standard Test Method for Rubber Property—Durometer Hardness." The durometer (Shore hardness) method for the solid rubber and foam grades on this page. store.astm.org (ASTM D2240)
Updated . Standards editions and links current at publication; verify against the publishing body before final spec. H-O materials are “aligned to” the standards cited; H-O does not certify systems, sound levels, or ordinance compliance. Lot-specific qualification documentation available on request.
To review your isolation or acoustic part, send:
- Equipment type and mass
- Pad bearing area (per pad)
- Forcing frequency / line freq / RPM
- Isolate / damp / absorb / barrier
- Indoor / outdoor + UV / ozone / oil
- Temperature & flame requirement
- Panel material & thickness (damping)
- Part or panel footprint drawing
- Adhesive / liner / lamination needs
- Prototype and annual volume
Get a power-equipment vibration & acoustic materials quote
Send a drawing, BOM, or a description of the vibration or noise problem. We typically respond within one business day with a material and part recommendation, prototype lead time, and TDS verification against your isolation tuning, sustained load, and absorption or barrier requirement.
See also: related H-O application pages
Engineering content for the adjacent energy, power, and renewable sub-applications and the parent hub. Each page covers material selection, failure modes, and converter-side process detail for its application family.
Sibling sub-application
Power systems thermal management
The heat side of the same equipment: thermal interface pads, gap fillers, and insulation for power systems.
Read the page
Sibling sub-application
Outdoor power & substation sealing
The weather-sealing playbook this page's outdoor EPDM pads draw from: enclosure gaskets and IP-rated closures for substation equipment.
Read the page
Sibling sub-application
Power assembly bonding & packaging
The bonding-and-cushioning side: die-cut acrylic-foam tapes and packaging that this page's damping patches share a material family with.
Read the page
Industry hub
Energy, power & renewable
The full energy, power, and renewable application family: insulation, thermal, EMI, arc-flash, sealing, bonding, vibration, and acoustics.
Read the page
Material data & standards. All compression, density, temperature, flame, and durometer values on this page are taken from the source maker's technical data sheets with the method named (ASTM D3574, D1056, D2240, D575, E756; UL 94 classes per the listed grade TDSs; absorption per ASTM C423 / E1050). Isolation theory (natural frequency, the √2 crossover, transmissibility, creep) is cited to named engineering references.
Transformer sound (IEC 60076-10, NEMA TR 1) and community-noise limits (local ordinance) are cited by designation only: they belong to the installed transformer, asset, and enclosure, and the materials on this page support the acoustic design. H-O converts materials; H-O does not manufacture transformers, run the sound-level test, or determine ordinance compliance, and does not independently certify materials against the standards unless explicitly stated on the quote.
Verify against the maker TDS and your acoustic and vibration evaluation plan.
Conversion scope. H-O and converts sheet, roll, and slab stock to drawing in Winsted, Connecticut: die-cut and kiss-cut pads, washers, and gaskets, slit materials, waterjet-cut thick pads and sections, laminated damping and barrier stacks, and kitted sets, with material traceability and lot-code TDS records. H-O does not perform molding or profile extrusion in-house; molded isolation mounts and extruded profiles are coordinated through a partner network. Lead-time and MOQ details are in the process strip and the quote form above.