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 151–200 of 220 products

SKU	ID	OD	Thickness	Material	ID TOL	OD TOL	Quantity
330-32-020	ID 0.093	OD 0.25	Thickness 0.02	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-33-020	ID 0.093	OD 0.281	Thickness 0.02	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-34-016	ID 0.093	OD 0.312	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-35-016	ID 0.093	OD 0.375	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-36-031	ID 0.099	OD 0.437	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-37-016	ID 0.105	OD 0.218	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-38-020	ID 0.105	OD 0.25	Thickness 0.02	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-39-031	ID 0.105	OD 0.281	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-40-016	ID 0.105	OD 0.312	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-41-031	ID 0.105	OD 0.35	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-42-016	ID 0.105	OD 0.375	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-43-016	ID 0.105	OD 0.437	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-44-062	ID 0.11	OD 0.219	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-45-031	ID 0.11	OD 0.5	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-46-016	ID 0.115	OD 0.187	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-47-020	ID 0.115	OD 0.25	Thickness 0.02	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-47-031	ID 0.115	OD 0.25	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-48-031	ID 0.115	OD 0.281	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-49-031	ID 0.115	OD 0.312	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-50-031	ID 0.115	OD 0.375	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-51-031	ID 0.115	OD 0.5	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-52-062	ID 0.115	OD 0.625	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-53-031	ID 0.125	OD 0.187	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-54-031	ID 0.125	OD 0.229	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-55-016	ID 0.125	OD 0.25	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-56-016	ID 0.125	OD 0.281	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-57-016	ID 0.125	OD 0.312	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-57-031	ID 0.125	OD 0.312	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-58-062	ID 0.125	OD 0.35	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-59-016	ID 0.125	OD 0.375	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-60-031	ID 0.136	OD 0.195	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-61-016	ID 0.136	OD 0.218	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-62-020	ID 0.136	OD 0.25	Thickness 0.02	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-63-031	ID 0.136	OD 0.281	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-64-031	ID 0.136	OD 0.312	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-65-031	ID 0.136	OD 0.375	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-66-093	ID 0.136	OD 0.5	Thickness 0.093	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-67-062	ID 0.136	OD 0.75	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-68-031	ID 0.136	OD 0.875	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-69-016	ID 0.141	OD 0.232	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-70-031	ID 0.141	OD 0.25	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-71-031	ID 0.141	OD 0.281	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-72-031	ID 0.141	OD 0.312	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-73-031	ID 0.141	OD 0.375	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-74-031	ID 0.141	OD 0.437	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-75-031	ID 0.141	OD 0.5	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-76-016	ID 0.148	OD 0.218	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-77-031	ID 0.148	OD 0.25	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-78-016	ID 0.148	OD 0.265	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-79-031	ID 0.148	OD 0.312	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.