Home › Blog › NVH & Vibration Control › How to spec an NVH part
How to Spec a Custom Die-Cut NVH or Vibration Part: What to Send H-O for a Quote
A fast, accurate quote on a custom die-cut NVH part comes down to a handful of inputs: the function the part does, the deflection or firmness target, the running speed and static load per pad or the drop it must survive, the temperature and environment, the adhesive configuration, the thickness, the geometry, and your prototype and annual volumes. This guide walks each input, explains why it matters, and ends with a spec builder that assembles your answers into a request you can paste straight into the quote form.
Request a quote for your project →
The application problem: an incomplete spec stalls the quote
H-O Products is a precision die-cut converter, and every isolation, damping, cushioning, or anti-rattle part is made to order from sheet, slab, or roll stock cut to your drawing. The concrete problem a buyer runs into is the stalled quote: a request that says "I need a vibration pad" without the function, the load, or the firmness target cannot be turned into a grade and a price without a follow-up. The inputs below are the same ones an applications engineer would ask for, so sending them up front turns a back-and-forth into a single response.
The first input does the most work. As covered in the companion guide on choosing between isolation, damping, and cushioning, the part is doing one of four jobs: isolation (lower a mounted natural frequency so a running machine is decoupled), damping (drain resonance out of a ringing panel), cushioning (limit the peak force during a drop or impact), or anti buzz-squeak-rattle (BSR) (kill a squeak or rattle). The rest of the spec branches from that answer, because the deciding property is different for each.
Why it is challenging: the deciding number changes with the function, and the system owns the result
Specifying an NVH part is harder than listing dimensions because the performance number that matters depends on the function, and because some results belong to the assembly rather than the part. An isolation part is specified around the running speed and the static load per pad, because those set the deflection that puts the operating point above the crossover. A damping part is specified around the loss factor needed to quiet a panel.
A cushioning part is specified around the drop energy and the peak force the protected item can tolerate. And a BSR part is specified around the contact and the closure force, not a load rating at all. On top of that, the mounted natural frequency, the transmissibility, and the cushion behavior are properties of the assembled system under its real load, so the part supports the result and your test plan confirms it.
The checklist below is organized around those realities.
What to send, input by input
1. The function, and the performance target that goes with it
- If it is isolation: the running speed (or disturbance frequency) and the static load carried per pad. These set the deflection and the grade that move the operating point above the crossover. A mount that is too stiff for the running speed amplifies rather than isolates, so the running speed is not optional.
- If it is damping: the panel or structure that rings and, if known, the frequency range of the resonance. Damping is ranked by loss factor (characterized per ASTM E756), so naming the problem frequency helps direct the grade.
- If it is cushioning: the drop height or impact energy and the peak force or deceleration the protected item can tolerate. These size the pad against the dynamic cushion curve (ASTM D1596) so it absorbs the drop without bottoming.
- If it is BSR: whether the noise is a squeak (stick-slip at a contact) or a rattle (hard contact across a gap), the contact geometry, and the closure force available.
2. Deflection force or firmness target (CFD)
Wherever a load is involved, send the firmness target as a deflection force rather than a subjective "soft" or "firm." For sponge and expanded rubber the firmness number is the compression-force-deflection (CFD), defined by ASTM D1056 as the force to reach 25 percent deflection; flexible cellular urethane firmness is characterized by the methods in ASTM D3574. A CFD target, or the force-versus-deflection window you need, removes the ambiguity and lets the grade be selected on the first pass.
3. Gap or compression target
Send the gap the part fills and the compression it will see in service, or the working deflection range. For an anti-rattle or take-up part this is the gap at low closure force; for a cushion it is the deflection budget before bottoming; for an isolation pad it is the static deflection under load. The gap and the firmness together decide whether a single grade and thickness can meet the target or whether a stack is needed.
4. Temperature and environment
Temperature and fluids select the material family before any firmness number:
- Oil, fuel, or road spray: a closed-cell, oil-resistant material such as vinyl nitrile, neoprene, or cork; natural rubber swells in oil and is avoided here.
- Outdoor, ozone, or UV: neoprene, EPDM, or silicone, which resist weather and ozone.
- High temperature or a flame rating: a silicone foam grade, which holds up at high temperature and carries flame-rated options; organic foams give way here. Name the standard you are designing to (for example UL 94 V-0) rather than "fireproof."
- Sustained static load over a long life: call this out, because compression set (per ASTM D395 and ASTM D1056) drives the long-term drift of an isolation mount off its design frequency, and a low-set material such as microcellular polyurethane is favored.
5. Adhesive, liner, and stack-up
Tell us whether the part needs a pressure-sensitive adhesive on one or both faces, a liner, a pull-tab for line placement, ribs or holes, or a laminated stack that combines a damping or barrier layer with a resilient one. Most NVH parts are adhesive-backed for repeatable placement, and an anti-squeak or anti-rattle part in particular has to land exactly on the contact line, so the adhesive and pull-tab are part of the function, not a finishing detail.
6. Thickness or gauge
Send the thickness or the thickness range. Thickness is the deflection budget: for isolation it sets the static deflection and therefore the natural frequency, and for cushioning it sets how much drop energy the pad absorbs before bottoming. Where a single available gauge does not reach the target, H-O can laminate or stack foam to a target thickness.
7. Geometry, footprint, or drawing
Send the footprint and the bearing geometry, or a dimensioned drawing. A drawing is the cleanest way to convey the footprint, thickness, hole or slot pattern, tolerances, and any adhesive callouts. If you do not have a formal drawing yet, a marked-up sketch with dimensions is enough to start a prototype.
8. Prototype and annual volume
Share both the prototype quantity and the expected annual volume. All parts are custom manufactured to order, and minimum production run quantities apply, so the volume shapes the converting approach and the tooling decision. Prototype quantities through full production are welcome.
The spec at a glance
| Input | Isolation | Damping | Cushioning | BSR |
|---|---|---|---|---|
| Performance target | Running speed + static load per pad | Loss factor / problem frequency | Drop energy + tolerable peak force | Squeak vs. rattle; contact + closure force |
| Firmness | CFD (force at 25 percent deflection) or working force-deflection window | Very low closure force | ||
| Environment | Temperature; oil / fuel; ozone / UV; flame rating (name the standard) | |||
| Build | Adhesive, liner, pull-tab, ribs / holes, laminated stack; thickness or range | |||
| Geometry | Footprint and bearing geometry, or a dimensioned drawing (DXF / STEP / PDF) | |||
| Commercial | Prototype quantity + annual volume | |||
NVH / Vibration Part RFQ Spec Builder
Function: Isolation (lower the mounted natural frequency; decouple a running machine) Performance target: running speed / disturbance frequency [to be provided]; static load per pad [to be provided] Firmness: CFD or force-deflection window [to be provided] Gap / compression target: [to be provided] Temperature: [to be provided] Environment / fluids: [to be provided] Build: standard die-cut; thickness [to be provided] Geometry: footprint / bearing geometry [to be provided] Compliance: none stated Commercial: prototype quantity [to be provided]; annual volume [to be provided] Drawing: to follow
Illustrative only; confirm against current material data and a drawing review. This builder formats your inputs into a request; it does not select a grade, compute a mounted natural frequency or transmissibility, or size a cushion. CFD, density, loss factor, compression set, and mounted natural-frequency values are confirmed on the manufacturer's current technical data sheet and in an H-O drawing review.
Transmissibility, natural frequency, and cushion behavior are properties of the assembled system under its real load and are validated by your test plan, not by the converted part alone.
Common failure modes in the spec itself
| Spec gap | Why it stalls the quote | The fix |
|---|---|---|
| "A vibration pad," no running speed | The deflection and grade cannot be set without the running speed and static load, and a too-stiff mount amplifies | Send the running speed and the static load per pad together |
| "Soft foam" with no firmness number | "Soft" is subjective; the grade is ambiguous | Send a CFD target or the force-deflection window you need |
| "Fireproof foam" | Not a grade designation; the right flame-rated grade is ambiguous | Name the standard, for example UL 94 V-0, and the temperature |
| Asking for a "guaranteed isolation efficiency" on the part | Transmissibility is a property of the assembled system under load, not of a converted pad | Send running speed and load; validate transmissibility on the assembly |
| No volumes | The converting and tooling approach depends on prototype versus production scale | Send both prototype quantity and annual volume |
How H-O Products helps
H-O Products is a precision die-cut converter. Once your spec is complete, we recommend a material family and grade direction across microcellular polyurethane, vinyl nitrile, neoprene and rebonded neoprene, EPDM sponge, natural rubber, cork and cork-rubber, silicone foam, and SAE pressed felt, then convert the stock to your drawing: die-cut, kiss-cut, laser or waterjet cut, laminated, slit to width, and kitted.
Documentation available on request includes the material technical data sheet, a certificate of conformance, lot traceability, and first-article inspection, all under our ISO 9001:2015 certified quality management system.
We do not produce the raw stock and we do not certify the finished assembly; grade properties are confirmed against the manufacturer's current technical data sheet, and the system-level vibration and shock behavior is validated by your test plan.
Send the spec, get a quote
Use the builder above to assemble your request, then paste it into the quote form with your drawing attached. We will recommend a grade direction and convert samples on your footprint.
Samples typically ship in 3 to 5 business days for common die-cut configurations; standard production runs about two weeks; special orders are quoted to the job.
Family-owned in Winsted, Connecticut since 1971 · ISO 9001:2015 certified · OEMs worldwide send us a drawing — and get back their part.
Related reading
Frequently asked questions
What information does H-O need to quote a custom NVH or vibration part?
Send the function (isolation, damping, cushioning, or BSR); for isolation the running speed and static load per pad; for cushioning the drop energy and tolerable peak force; a firmness target as CFD (force at 25 percent deflection) or a force-deflection window; the gap or compression target; the temperature and environment (oil, ozone, UV, flame rating named by standard); the adhesive, liner, and stack-up; the thickness or range; the footprint or a drawing; and both the prototype quantity and the annual volume.
Why do you need the running speed for an isolation pad?
The running speed and the static load per pad together set the static deflection, which sets the mounted natural frequency and decides whether the operating point lands in the isolation region above the crossover or in the amplification region near resonance. A mount that is too stiff for the running speed amplifies the vibration rather than isolating it, so a firmness alone, with no running speed, leaves the most important question open.
How should I specify firmness, and what is CFD?
Specify firmness as a deflection force rather than a subjective soft or firm. For sponge and expanded rubber the firmness number is the compression-force-deflection (CFD), defined by ASTM D1056 as the force to reach 25 percent deflection; flexible cellular urethane firmness is characterized by the methods in ASTM D3574. Sending a CFD target or the force-versus-deflection window you need lets the grade be selected on the first pass instead of after a round-trip.
Does H-O have a minimum order quantity?
All parts are custom manufactured to order and minimum production run quantities apply, varying by material and part. Prototype quantities through full production are welcome, so sending both the prototype quantity and the expected annual volume lets H-O recommend the right converting and tooling approach. H-O is a die-cut converter and does not produce the raw stock or certify the finished assembly.
Request a quote for your NVH, shock & vibration control part
Send H-O your drawing or describe the part—engineering reviews every RFQ and converts samples on your geometry.
Last updated · Reviewed by H-O Products engineering (ISO 9001:2015 certified converter, Winsted, CT).
References
- ASTM D1056 (sponge and expanded rubber, including CFD at 25 percent deflection) and ASTM D395 (rubber compression set). ASTM International.
- ASTM D3574 (flexible cellular urethane test methods). ASTM International.
- ASTM E756 (vibration-damping loss factor) and ASTM D3580 (vibration / resonance search). ASTM International.
- ASTM D1596 (dynamic shock cushioning). ASTM International.
- UL 94 (flammability). UL Standards.
- Manufacturer technical data sheets: microcellular polyurethane, vinyl nitrile, neoprene and EPDM sponge, silicone foam, and felt.
This article cites general engineering principles and published standards (ASTM D1056 for sponge and expanded rubber including CFD at 25 percent deflection, ASTM D3574 for flexible cellular urethane test methods, ASTM D395 for rubber compression set, ASTM E756 for vibration-damping loss factor, ASTM D1596 for dynamic shock cushioning, ASTM D3580 for vibration / resonance search of products, and UL 94 for flammability).
Material names refer to material families H-O Products converts. CFD, density, loss factor, compression set, mounted natural-frequency, and flame-classification values are grade- and application-specific; confirm all values against the manufacturer's current technical data sheet and an engineering drawing review. All parts are custom manufactured to order and minimum production run quantities apply. H-O is a die-cut converter, not a raw-material producer, and does not certify the finished assembly.