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How to Spec Aerospace Machine Insulation: What to Send H-O for a Quote
Aerospace machine insulation attracts underspecified quote requests because the geometry looks like the whole story: a liner outline, a standoff, a film barrier. What the quote actually prices is the duty behind it, the hot-spot thermal class, the dielectric duty including altitude, the mechanical role, and whether the deliverable is a single part or a kitted system. This is the ten-item checklist the H-O applications team works from, what engineering does with each item, and what comes back.
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The ten things to send, and what each decides
Aerospace machine insulation attracts underspecified RFQs because the geometry looks like the whole story: a liner outline, a standoff, a film barrier. What the quote actually prices is the duty behind the geometry: the hot-spot thermal class, the dielectric duty including altitude, the mechanical role, the forming the winding room needs, and whether the deliverable is a single part or a kitted system.
This is the ten-item checklist the H-O applications team works from for liners, separators, wraps, barriers, standoffs, and pads, drawn from the parent application page's own engineering-review list, plus what engineering does with each item and what comes back.
| Send this | What it decides |
|---|---|
| 1. Thermal class at the real hot spot | The family list. The IEC 60085 class at the measured or modeled hot spot, derated for altitude and duty, not the ambient. The class line is the life of the machine. |
| 2. Dielectric duty: working, test, and altitude | Breakdown margin per ASTM D149 and, for high-voltage DC, the altitude-derated partial-discharge case rather than the sea-level rule. |
| 3. Mechanical role: liner, barrier, or structure | Paper or film for liners and wraps, mica for arc barriers, glass-epoxy or tracking-resistant laminate for structure, silicone for compliant pads. |
| 4. System voltage class | 115 VAC versus the 270 VDC more-electric class of MIL-STD-704, which adds film-tier barriers and engineered creepage. |
| 5. Bay environment | Fluids, condensation, and conductive contamination push standard laminates toward tracking-resistant composites with engineered creepage geometry. |
| 6. Forming and creasing | Crease lines, fold geometry, and insertion path, so the converted part seats without trapping voids or cracking at a fold. |
| 7. Converting and inspection quality | Burr-free edges, void-free seating, and incoming inspection on edges, not just dimensions, because breakdown per ASTM D149 assumes intact material. |
| 8. Kit scope: part or system | Single detail or a drawing-controlled insulation kit, every liner, separator, wrap, wedge, and washer in winding order, lot-traceable across shops and years. |
| 9. Geometry and lamination drawing: DXF, STEP, or PDF | Footprint, crease lines, creepage dimensions, and lamination order, the items that make the kit reproducible. |
| 10. Prototype and production volumes | Converting method and price structure. Every part is made to order; prototype quantities through production and rewind runs are equally accepted, and MOQ varies by material and part. |
What engineering does with the list
Items 1 through 4 pick the family by class, dielectric duty, role, and voltage: Nomex aramid liners and separators, Kapton wraps and laminations, mica arc barriers, and APTIV PEEK barriers where item 4 names the 270 VDC class. Item 5 steers standoffs from G10 or FR4 to Durostone-class composites where the bay is contaminated. Items 6 and 7 become the forming plan and the edge-quality standard, with the compliant pads on BISCO HT-12xx silicone. Items 8 through 10 become the kit scope, the lamination drawing, and the price structure.
What happens after you send it
- Drawing review. Engineering reviews the system against the vendor TDS: hot-spot class, dielectric duty and altitude, mechanical role, voltage class, bay environment, and forming.
- Material direction and quote. A family and grade direction with the TDS attached, the converted format (die-cut, machined, laminated, creased), the kit scope, and pricing at your quantities.
- Samples. Typically 3 to 5 business days for common die-cut configurations on materials we keep on hand.
- Production. Standard runs ship about two weeks after drawing approval, including kitted insulation systems in winding order; expedited service is available. Ongoing parts run with material traceability and lot-code TDS records.
Documentation available on request: material technical data sheet, certificate of conformance, and lot traceability, under our ISO 9001:2015 certified quality management system. H-O is a die-cut converter, not a raw-material producer: we do not manufacture the raw paper, film, mica, or laminate, we do not independently certify them, and insulation-system design and machine qualification belong to the OEM.
The mistakes this checklist prevents
| Spec mistake | What it causes | Checklist item that catches it |
|---|---|---|
| Class assigned to the ambient | Aging on the wrong curve, halved life | Item 1, hot-spot class |
| 270 VDC barrier by sea-level habit | Partial discharge erodes the margin at altitude | Items 2 and 4, altitude case |
| G10 standoff in a contaminated bay | Surface tracking, phase-to-ground fault | Item 5, tracking-resistant composite |
| Liner nicked at insertion | Hi-pot failure now, or breakdown later | Item 7, edge quality |
| Rewind insulation improvised | Untraceable, unrepeatable machine | Item 8, drawing-controlled kit |
| Barrier installed with a void beside it | Reintroduced partial-discharge weak point | Items 6 and 7, void-free seating |
Frequently asked questions
What information do I need to send H-O to quote an aerospace insulation part?
Ten items turn the geometry into a quotable drawing: the thermal class at the real hot spot, the dielectric duty (working, test, and altitude), the mechanical role, the system voltage class, the bay environment, the forming and creasing, the converting and inspection quality required, the kit scope (part or system), the geometry and lamination drawing as DXF, STEP, or PDF, and the volumes. Send what you have; engineering frames the rest and flags any assumption.
Can H-O cross-reference the insulation grade on my lamination drawing?
In most cases, yes. If your drawing calls out an aramid paper, polyimide or PEEK film, mica, or laminate by a brand part number or an IEC, NEMA, or MIL designation, engineering identifies a comparable grade from the lines we convert, matching on thermal class per IEC 60085, breakdown per ASTM D149, laminate grade per NEMA LI 1, and the tracking and altitude behavior the location requires. It is an industry cross-reference, not a guaranteed drop-in, verified against the vendor TDS before quoting.
Can H-O kit complete insulation systems for OEM lines and rewind shops?
Yes, and it is the deliverable that makes a rewind reproducible. Instead of liners cut by hand and wraps substituted by availability, H-O builds the insulation system as a drawing-controlled product: every liner, separator, wrap width, wedge, and washer die-cut to the lamination drawing, labeled in winding order, lot-traceable, and repeatable across shops and years. The same kit serves an OEM production line and a rewind program, which removes the untraceable improvisation that makes a rewound machine behave differently.
Why does converting quality matter as much as the material choice?
Because breakdown values per ASTM D149 assume intact material, but the slot only ever contains the material as converted. A liner with edge burrs from a worn tool, scuffed during insertion, hides damage under the winding until test voltage or two thousand service hours finds it; and at high voltage a void beside a barrier reintroduces a partial-discharge weak point.
So burr-free edges, crease placement that seats without trapping air, and incoming inspection that looks at edges, not just dimensions, are part of the dielectric specification, not a cosmetic nicety.
What lead time should I expect for samples and production?
Every insulation part is made to order, including samples. Samples typically ship in 3 to 5 business days for common die-cut configurations on materials we keep on hand; standard production runs ship about two weeks after drawing approval, including kitted insulation systems in winding order; expedited service is available when timing is critical. MOQ varies by material and part, and prototype quantities through production and rewind runs are equally accepted.
Send the checklist, get a machine insulation quote
Attach the lamination drawing and as many of the ten items as you have. If something is unknown, say so; the review proceeds with the assumption flagged.
Samples typically ship in 3 to 5 business days for common die-cut configurations on materials we keep on hand; standard production runs about two weeks after drawing approval; expedited service is available. MOQ varies by material and part.
Family-owned in Winsted, Connecticut since 1971 · ISO 9001:2015 certified · OEMs worldwide send us a drawing — and get back their part.
Related reading
Request a quote for your aerospace electrical insulation 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
- IEC 60085 (thermal classification, the family-sorting framing); ASTM D149 (dielectric breakdown voltage and strength).
- NEMA LI 1 (industrial laminate grades, by designation); MIL-I-24768 (laminate military specification family, by designation).
- MIL-STD-704 (aircraft electric power characteristics, including the 270 VDC class, cited qualitatively); RTCA DO-160 (environmental framing).
- UL 94 (flammability listings, per grade and thickness).
- Manufacturer technical data sheets for the aramid paper, polyimide and PEEK film, mica, glass-epoxy and tracking-resistant laminate, and silicone grades named on the parent application page.
This article summarizes electrical-insulation material-selection principles for aerospace machines and power systems using the families and published test methods cited on the parent application page. Comparisons are qualitative; per-grade values and thermal-class assignments quoted are maker-TDS figures and must be confirmed on the manufacturer's current technical data sheet at your hot spot, voltage, and altitude. Standards (IEC, ASTM, NEMA, MIL-STD) are cited by designation for context, not as a claim of qualification.
H-O is a precision die-cut converter, not a raw-material producer, and does not design insulation systems, certify machines, or perform dielectric qualification; those belong to the machine OEM and its test houses.