G10 / FR-4 Epoxy Glass Insulating Washers and Spacers
Precision epoxy glass washers for terminal and busbar insulation. G10/FR-4 washers give moisture-stable insulation at terminal and busbar joints. We machine them to ID/OD and thickness with flatness held across the batch. For high volume we tool stamping and supply inspection records on request. Stamped for high volume and burr-free edges; machined when ID/OD or flatness must be tight.
Technical specifications
| Material | G10 / FR-4 epoxy glass |
| Property | Moisture stable, V-0 (FR-4) |
| Tolerance | Thickness +/-0.05 to 0.10 mm |
| Use | Terminal / busbar washers |
Applications by industry
- Insulating washers under busbar and device mounting bolts
- Spacer shims between live and earth metalwork
- CB terminal pad isolating washers
- High-strength flange washers in electrical machinery
- PCB standoff/insulation washers (FR-4)
- Custom-ID/OD punched washers for transformer hardware
Why G10 / FR-4 epoxy glass for this application
G10/FR-4 washers isolate hardware while carrying the clamp load of a torqued bolt, which paper phenolic alone often crushes under. Punching keeps cost low and hole concentricity repeatable.
p>Confirm thickness-class against crush and CTI of the surrounding duty. Punched FR-4 edge can be brittle near a tighten bolt. Specify chamfered or ground if torque is high. specify chamfered or ground if torque is high.Standards: IPC-4101 / ASTM D709, IEC 60672, UL 94 V-0.
Feature and remaining-wall review
G10 / FR-4 Epoxy Glass Insulating Washers is machined with diamond-coated tooling for clean edges, then CNC turned, ground and drilled to drawing. With moisture content controlled, dimensional stability holds. Feature depth, edge distance and remaining wall are checked against the critical geometries, and capability is confirmed on your drawing rather than a blanket tolerance.
Inspection and traceability
We state the control plan with you. Batch traceability links raw material lot to finished part.
- First-article inspection (FAI) per your plan
- In-process dimensional checks at every station
- Batch certificate of conformance (COA) supplied on request
- Lot traceability to incoming material certificate
- Dielectric strength and insulation resistance testing available on request
Related components
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GPO-3 Polyester Glass Sheet
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ECR Epoxy Fiberglass Rods
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Common questions
Where would you specify G10 / FR-4 Epoxy Glass Insulating Washers and Spacers?
Typical applications are terminal / busbar washers. Describe the duty and the environment, and we will confirm whether G10 / FR-4 Epoxy Glass Insulating Washers is the right grade for it.
Which material is G10 / FR-4 Epoxy Glass Insulating Washers and Spacers manufactured from?
The material is G10 / FR-4 epoxy glass. Alternate grades can be quoted against your drawing.
Is a material certificate of analysis provided for G10 / FR-4 Epoxy Glass Insulating Washers and Spacers?
We issue a material COA with each batch of G10 / FR-4 Epoxy Glass Insulating Washers. Where your file asks for first-article inspection or dielectric strength testing, those reports are included as well.
Can G10 / FR-4 Epoxy Glass Insulating Washers and Spacers be produced to a customer drawing?
ID, OD and thickness are supplied to your drawing. Send the print with the quantity you need and we will quote to it.
Engineering Guides & Selection Notes
Related reading on the selection and specification decisions behind G10 / FR-4 Epoxy Glass Insulating Washers.
Get pricing for G10 / FR-4 Epoxy Glass Insulating Washers and Spacers
The quote for G10 / FR-4 Epoxy Glass Insulating Washers starts from your drawing and the annual volume. We verify the material against the duty and tolerance, confirm ID, OD, wall and every feature of G10 / FR-4 Epoxy Glass Insulating Washers, and reply with manufacturing notes and pricing.