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How to Spec an E-Axle Insulation or Seal Part: What to Send H-O for a Quote
A fast, accurate quote on a die-cut e-axle part comes down to nine inputs: the function (slot liner, phase barrier, wedge, or seal), the target thermal class and hot-spot temperature, the working voltage and dielectric margin, the slot or seal geometry, the slot-fill and mechanical loads, the fold and insertion method, the varnish, oil or coolant exposure, the adhesive and liner configuration, 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 contact form.
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The application problem: an incomplete spec stalls the quote
H-O Products is a precision die-cut converter, and every slot liner, phase barrier, wedge and gearbox seal is made to order from sheet, film or roll stock cut to your drawing. The concrete problem a buyer runs into is the stalled quote: a request that says "I need motor insulation" without the location, the voltage or the temperature 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 slot, phase and wedge materials, the part is doing one of four jobs: slot liner / ground wall (survive insertion, hold the slot-to-ground voltage), phase or layer barrier (maximum dielectric in minimum thickness), wedge or end-turn support (hold conductors mechanically when hot), or gearbox / shaft-area seal (hold a compression seal in hot oil). The rest of the spec branches from that answer.
Why it is challenging: the deciding numbers come in pairs, and the system owns the class
An e-axle spec is harder than a dimension list because the governing values arrive in pairs: thermal class with real hot-spot temperature, working voltage with dielectric margin, slot geometry with insertion method, lubricant with temperature. One member of each pair without the other leaves the grade ambiguous.
On top of that, the rating most often quoted, the insulation-system thermal class, belongs to the complete system qualified under IEC 60034-18 within the framework of UL 1446, so the converted part supports the class and your qualification confirms it.
The checklist below is organized around those realities.
What to send, input by input
1. The function
Name the location: slot liner / ground wall, phase or layer barrier, slot wedge or end-turn support, or gearbox / shaft-area seal. Each maps to a different lead family, aramid paper, polyimide film, PEEK film, and fluorosilicone sponge respectively, so this single word directs the rest of the review.
2. Target thermal class and hot-spot temperature
Send both the class you are designing to (for example Class H) and the real hot-spot temperature. The class belongs to the qualified insulation system, so the honest spec states the system target and lets the material's data-sheet reach be matched to it, rather than asking for "a Class H sheet" in isolation.
3. Working voltage and dielectric margin
For liners and barriers, send the working voltage at the location (slot-to-ground or phase-to-phase) and the margin you carry for the inverter's fast switching edges. These two numbers, against the grade's data-sheet dielectric strength per unit thickness, set the gauge. For the highest-voltage designs, note any partial-discharge consideration.
4. Slot or seal geometry, or a drawing
A dimensioned drawing (DXF, STEP or PDF) is the cleanest input: it carries the profile, the thickness, the fold lines, the cuff detail and the tolerances in one artifact. If a formal drawing does not exist yet, a marked-up sketch of the slot profile or seal cross-section with dimensions is enough to start a prototype.
5. Slot fill and mechanical loads
For wedges and end-turn supports, send the holding loads and the slot-fill condition. A wedge is a mechanical part first: stiffness and dimensional stability at the hot-spot temperature decide the material, and the loads decide whether PEEK film, a denser calendered aramid, or a rigid glass-composite laminate carries the job.
6. Fold, cuff and insertion method
Tell us how the motor is wound and inserted. Insertion is where liners fail, so the scored fold lines, the creases, the cuffs at the slot ends and the seating allowance are converting features matched to your process, not afterthoughts.
7. Varnish, oil and coolant exposure
Name the varnish system, the gearbox lubricant, and any oil-spray or coolant contact, with temperatures. Fluid exposure decides elastomer chemistry (fluorosilicone versus FKM) and can influence film and laminate choices in wet and oil-cooled motors.
8. Adhesive, liner and lamination
State whether the part needs a pressure-sensitive adhesive, a liner, a pull-tab, or a laminated build such as aramid-polyimide-aramid. Lamination is how one converted part carries both toughness and dielectric, so it belongs in the spec rather than the margin notes.
9. 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 | Liner | Phase barrier | Wedge | Seal |
|---|---|---|---|---|
| Electrical | Slot-to-ground voltage + margin | Phase-to-phase voltage + margin; partial discharge if highest-voltage | Secondary | Not applicable |
| Thermal | Target system class + real hot-spot temperature | Continuous oil temperature | ||
| Mechanical | Insertion method; fold / cuff detail | Handling; laminate carrier if needed | Holding loads; slot fill | Compression and recovery |
| Chemical | Varnish system; coolant spray if oil-cooled | Oils / solvents | Lubricant named | |
| Build | Thickness or range; adhesive / liner / pull-tab; laminated stack if any | |||
| Geometry | Profile or dimensioned drawing (DXF / STEP / PDF) | |||
| Commercial | Prototype quantity + annual volume | |||
E-Axle Insulation / Seal RFQ Spec Builder
Function: Slot liner / ground wall Thermal: target class + hot-spot [to be provided] Electrical: working voltage + margin [to be provided] Geometry: [to be provided] Mechanical: slot fill / loads [to be provided] Insertion: fold / cuff / method [to be provided] Fluids: varnish / oil / coolant [to be provided] Build: standard die-cut; thickness [to be provided] Compliance notes: 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, set a gauge, or assert an insulation-system class. Dielectric, thermal, stiffness and fluid-compatibility values are confirmed on the manufacturer's current technical data sheet and in an H-O drawing review, and the system class is established by your qualification under IEC 60034-18 / UL 1446.
Common failure modes in the spec itself
| Spec gap | Why it stalls the quote | The fix |
|---|---|---|
| "Motor insulation," no location | Liner, barrier, wedge and seal point at four different families | Name the location; the family follows |
| "Class H material," no hot-spot | The class belongs to the qualified system; the material is matched by reach | Send the target class and the real hot-spot temperature together |
| Voltage without margin | Gauge cannot be set from one number; switching edges need headroom | Send working voltage plus design margin as a pair |
| No insertion method | Fold, crease and cuff detail cannot be placed; liner survival is unproven | Describe how the motor is wound and inserted |
| "Oil-resistant seal," no lubricant named | Fluorosilicone versus FKM is decided by the specific fluid and temperature | Name the lubricant and the continuous temperature |
| 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 working across EV and battery programs. Once your spec is complete, we recommend a family and grade direction across aramid paper, polyimide film, PEEK film, mica barrier sheet, composite laminates and fluorosilicone sponge, then convert the stock to your drawing: die-cut, kiss-cut, scored and creased, laser or waterjet cut, laminated, slit 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; the insulation-system class is earned by your qualified system.
Send the spec, get a quote
Use the builder above to assemble your request, then send it through the contact page with your drawing attached. We will recommend a grade direction and convert samples on your profile.
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
IndustryEV & Battery materials overviewRead →
Frequently asked questions
What should I send to get a quote on a traction-motor insulation part?
Nine inputs: the function (slot liner, phase barrier, wedge, or seal), the target thermal class and real hot-spot temperature, the working voltage and dielectric margin, the slot or seal geometry or a drawing, the slot-fill and mechanical loads, the fold and insertion method, the varnish, oil or coolant exposure, the adhesive and lamination requirements, and the prototype and annual volumes. With those, a converter can recommend a family and grade direction in one pass.
Can a converted insulation part be certified to IEC 60034-18 or UL 1446?
Those standards classify an insulation system, not a single converted part. IEC 60034-18 is a functional-evaluation method for a motor's complete insulation system, and UL 1446 is the framework for thermal classes of insulation systems and their recognized component materials. A slot liner or phase barrier is a component that supports a system; the class is earned by the system tested as a whole, so state your target class and let the material be matched by its data-sheet reach.
Do I need a formal drawing to get a prototype quoted?
No. A dimensioned drawing in DXF, STEP or PDF is the cleanest input because it carries the profile, thickness, fold lines, cuffs and tolerances in one artifact, but a marked-up sketch of the slot profile or seal cross-section with dimensions is enough to start a prototype. Volumes still matter: send the prototype quantity and the expected annual volume so the converting and tooling approach can be set.
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Last updated · Reviewed by H-O Products engineering (ISO 9001:2015 certified converter, Winsted, CT).
References
- IEC 60034-18, Rotating electrical machines: functional evaluation of insulation systems. International Electrotechnical Commission.
- UL 1446, Systems of Insulating Materials, General. UL Standards.
- IEC 60317, Specifications for particular types of winding wires. International Electrotechnical Commission.
- Manufacturer technical data sheets for the grades under review; dielectric, thermal and fluid-compatibility values are grade-specific.
This article cites general engineering principles and published standards (IEC 60034-18 and UL 1446 for insulation-system thermal classification, IEC 60317 for winding wire). Material names refer to material families H-O Products converts.
Dielectric strength, temperature reach, stiffness and fluid-compatibility 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.