Vulcanized Fiber (Fish Paper) Washers and Spacers
Arc-resistant washers and spacers punched or machined to drawing. Vulcanized fiber washers are the arc-resistant choice for fuse and switchgear joints. We punch or machine them to ID/OD and thickness. Punched washers are burr-free; machined ones hold tighter ID/OD for close-fit spacers. Punched for volume and burr-free edges; machined for tight ID/OD. We pick from tolerance. Rolled and machined vu
Arc-resistant washers and spacers punched or machined to drawing. Vulcanized fiber washers are the arc-resistant choice for fuse and switchgear joints. We punch or machine them to ID/OD and thickness. Punched washers are burr-free; machined ones hold tighter ID/OD for close-fit spacers. Punched for volume and burr-free edges; machined for tight ID/OD. We pick from tolerance. Rolled and machined vu
Technical specifications
| Material | Vulcanized fiber (fish paper) |
| Property | Arc-resistant |
| Form | Punched or machined |
| Use | Fuse / switchgear washers |
💾 Datasheets & Test Reports
Download the technical data sheet for this product (PDF).
Information required for quotation
| Base tube | Approved material grade, ID, OD, wall and conditioning as per drawing |
| Datums | Drawing datum scheme and measurement reference |
| Key dimensions | Feature positions, depths, pitch and diameters reviewed before quotation |
| Thread / profile | Standard or custom profile, class, depth, engagement and gage method |
| Other features | Holes, slots, steps, chamfers, cuts and marking |
| Acceptance | Tolerances, sampling, gages, FAI and inspection report |
| Order | Prototype and production quantity, packaging and delivery target |
Applications by industry
- Insulating washers under panel and terminal screws
- Fish-paper spacer washers in relays and contactors
- Machine- and die-cut washers for LV assembly
- Bobbin and coil end washers
- Low-cost barrier washers between stacked terminations
- Custom OD/ID punched washers for hardware isolation
Why vulcanized fiber for this application
Vulcanized fibre washers isolate and center hardware in compact LV assemblies, and punch cheaply and cleanly at volume with stable dielectric per thickness.
Hydrophilic; washer swells if wet. Confirm stack compression and CTI in the surrounding duty.
Standards: ASTM D2491, UL 94 V-0 (grade dependent).
Feature and remaining-wall review
ID/OD ground or turned; CNC knurling, threading, slotting and cutting to drawing. Feature depth and remaining wall reviewed pre-quotation. Review feature depth, edge distance and remaining wall against critical geometries. Capability is confirmed on your drawing, not from 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
Custom Vulcanized Fiber Tubes
Related insulation component from the WELLELE catalog.
G10 / FR-4 Epoxy Glass Washers
Related insulation component from the WELLELE catalog.
Vulcanized Fiber (Fish Paper) Sheet
Related insulation component from the WELLELE catalog.
Common questions
What is the standard for vulcanized fiber tubes used in fuse assemblies?
Vulcanized fiber tubes for fuse bodies are referenced to IEC 60269 for body dimensions and end-cap geometry. Material follows ASTM D2491 (fish paper) and UL 94 V-0 for flammability. Specify the fuse link type and voltage class and we confirm the grade and tolerance.
What tolerance can you hold on vulcanized fiber tubes?
On thin-wall vulcanized fiber sections we typically hold ±0.05 mm on ID and OD. Knurl pitch, major/minor diameter and position are reviewed per drawing. Capability is confirmed against your print, not published as a blanket claim.
Is vulcanized fiber suitable for arc-facing fuse applications?
No. For arc-facing surfaces, use ceramic-filled epoxy glass, melamine or synthetic arc-quenching composites. Vulcanized fiber is for non-arc-facing mechanical bodies and end caps.
Can you supply COA and batch traceability?
Every batch is traceable to the incoming material certificate. Material COA, first-article inspection (FAI), in-process checks and final inspection reports are supplied per your plan on request.
Punched or machined vulcanized fiber washer?
Every batch is traceable to the incoming material certificate. Material COA, first-article inspection (FAI), in-process checks and final inspection reports are supplied per your plan on request.
Engineering Guides & Selection Notes
Related technical articles that help specify this product.
Get pricing for Vulcanized Fiber (Fish Paper) Washers and Spacers
Attach the drawing with annual volume. We check the material against your duty and tolerance, verify ID / OD / wall / features, and respond with manufacturability notes and pricing.