Fiber Flat Washers - Non-Conductive Hard Fiber Washers

Fiber flat washers made from hard vulcanized fiber provide electrical insulation, moderate chemical resistance, and lightweight performance for industrial, electrical, and commercial applications. Superior Washer & Gasket Corp manufactures hard fiber washers in standard and custom sizes as a cost-effective non-metallic washer solution.

Our ISO 9001:2015 certified specialty washer capabilities include hard fiber, felt, fiberglass, and phenolic washers in a wide range of thicknesses and OD/ID dimensions. Custom fiber washers are produced to your exact specifications and made in the U.S.A. with fast lead times.

Hard vulcanized fiber for electrical insulation
Lightweight and cost-effective non-metallic option
Standard and custom fiber washer sizes
ISO 9001:2015 certified quality management
Made in the U.S.A.

Showing 51–100 of 220 products

SKU	ID	OD	Thickness	Material	ID TOL	OD TOL	Quantity
330-143-016	ID 0.281	OD 0.625	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-144-031	ID 0.281	OD 0.687	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-145-031	ID 0.281	OD 0.75	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-146-062	ID 0.315	OD 0.437	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-147-031	ID 0.315	OD 0.5	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-148-016	ID 0.315	OD 0.562	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-149-062	ID 0.315	OD 0.625	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-15-016	ID 0.062	OD 0.187	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-150-016	ID 0.315	OD 0.687	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-151-031	ID 0.315	OD 0.75	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-152-031	ID 0.32	OD 0.562	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-153-031	ID 0.32	OD 0.625	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-154-031	ID 0.32	OD 0.75	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-155-062	ID 0.343	OD 0.875	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-156-031	ID 0.378	OD 0.5	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-157-031	ID 0.378	OD 0.625	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-158-031	ID 0.378	OD 0.75	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-159-062	ID 0.378	OD 0.812	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-16-016	ID 0.062	OD 0.218	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-160-031	ID 0.385	OD 0.625	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-160-062	ID 0.385	OD 0.625	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-161-031	ID 0.39	OD 0.629	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-162-062	ID 0.39	OD 1.0	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-163-031	ID 0.406	OD 0.625	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-164-062	ID 0.406	OD 1.0	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-165-062	ID 0.43	OD 0.85	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-166-031	ID 0.437	OD 0.687	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-167-062	ID 0.443	OD 0.75	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-167M-015	ID 0.5	OD 0.75	Thickness 0.015	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-168-031	ID 0.443	OD 0.875	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-169-031	ID 0.448	OD 0.688	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-17-016	ID 0.062	OD 0.312	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-170-031	ID 0.5	OD 0.625	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-171-062	ID 0.505	OD 0.625	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-172-031	ID 0.505	OD 0.75	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-173-031	ID 0.515	OD 0.875	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-174-045	ID 0.525	OD 1.0	Thickness 0.045	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-175-062	ID 0.531	OD 1.5	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-176-031	ID 0.562	OD 0.812	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-177-062	ID 0.562	OD 1.25	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-178-031	ID 0.625	OD 0.75	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-178-062	ID 0.625	OD 0.75	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-179-062	ID 0.625	OD 0.873	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-18-016	ID 0.062	OD 0.375	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-180-093	ID 0.656	OD 1.312	Thickness 0.093	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-181-031	ID 0.687	OD 0.937	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-181-062	ID 0.687	OD 0.937	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-182-015	ID 0.75	OD 1.0	Thickness 0.015	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-182-031	ID 0.75	OD 1.0	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-183-031	ID 0.75	OD 1.062	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity

Fiber Flat Washer Frequently Asked Questions

Below are answers to some of the most common questions about fiber flat washers.

What are fiber flat washers?
Fiber flat washers are manufactured from vulcanized fiber, a dense, rigid material made from chemically treated cellulose (cotton or wood pulp). Vulcanized fiber is non-conductive, non-magnetic, lightweight, and tough, and has been used as an electrical and mechanical insulating material in industrial applications for over a century.

What are fiber washers used for?
Fiber washers are commonly used as electrical insulators between metal components, as cushioning washers to prevent surface damage, and in applications requiring a non-conductive, non-metallic washer that is tougher than plastic but more economical than engineered resins. They are used in switchgear, electrical panels, automotive assemblies, and general industrial fastener applications.

How does vulcanized fiber differ from plastic washer materials?
Vulcanized fiber is a natural cellulose-based material, not a synthetic polymer. It is generally denser and tougher than many plastics, with good machinability and excellent dielectric properties. It absorbs more moisture than synthetic plastics, which can cause dimensional changes in high-humidity environments, but it remains a cost-effective choice for many electrical insulation applications.

Can you make custom fiber flat washers?
Yes. Superior Washer manufactures custom fiber washers to your OD, ID, and thickness specifications. Contact us via the Quick Quote form or by phone.

Are your fiber flat washers made in the USA?
Yes. All fiber flat washers are manufactured in the United States under our ISO 9001:2015 certified Quality Management System. Material certifications are available upon request.

Vulcanized fiber is one of many non-metal options we produce. Browse our full range of flat washers to compare materials and find the best fit for your application.