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 101–150 of 220 products

SKU	ID	OD	Thickness	Material	ID TOL	OD TOL	Quantity
330-183-062	ID 0.75	OD 1.062	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-184-062	ID 0.75	OD 1.625	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-185-031	ID 0.785	OD 1.25	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-186-031	ID 0.785	OD 1.437	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-187-031	ID 0.812	OD 1.125	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-188-093	ID 0.812	OD 1.469	Thickness 0.093	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-189-015	ID 0.875	OD 1.187	Thickness 0.015	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-189-031	ID 0.875	OD 1.187	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-189-062	ID 0.875	OD 1.187	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-19-010	ID 0.068	OD 0.125	Thickness 0.01	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-190-031	ID 0.937	OD 1.25	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-191-016	ID 0.958	OD 1.125	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-192-062	ID 1.0	OD 1.312	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-193-015	ID 1.0	OD 2.625	Thickness 0.015	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-194-031	ID 1.381	OD 1.75	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-195-031	ID 0.157	OD 0.275	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-196-020	ID 0.128	OD 0.251	Thickness 0.02	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-197-091	ID 0.256	OD 0.501	Thickness 0.091	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-198-030	ID 0.108	OD 0.363	Thickness 0.03	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-20-016	ID 0.068	OD 0.187	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-200-064	ID 0.311	OD 0.903	Thickness 0.064	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-201-021	ID 0.402	OD 0.976	Thickness 0.021	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-202-020	ID 0.563	OD 1.436	Thickness 0.02	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-205-020	ID 0.128	OD 0.274	Thickness 0.02	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-206-090	ID 0.141	OD 1.182	Thickness 0.09	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-207-020	ID 0.196	OD 0.375	Thickness 0.02	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-208-060	ID 0.13	OD 0.246	Thickness 0.06	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-209-046	ID 0.314	OD 0.503	Thickness 0.046	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-21-016	ID 0.068	OD 0.218	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-210-046	ID 0.203	OD 0.45	Thickness 0.046	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-213-062	ID 0.185	OD 0.385	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-214-014	ID 0.1	OD 0.155	Thickness 0.014	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-215-046	ID 0.116	OD 0.249	Thickness 0.046	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-216-033	ID 1.0	OD 1.498	Thickness 0.033	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-217-032	ID 0.219	OD 0.313	Thickness 0.032	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-218-047	ID 0.156	OD 0.351	Thickness 0.047	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-219-062	ID 0.323	OD 0.625	Thickness 0.062	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-22-016	ID 0.068	OD 0.25	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-220-031	ID 0.078	OD 0.392	Thickness 0.031	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-221-040	ID 0.205	OD 0.375	Thickness 0.04	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-222-032	ID 0.315	OD 1.249	Thickness 0.032	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-23-016	ID 0.068	OD 0.312	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-24-016	ID 0.084	OD 0.156	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-25-016	ID 0.084	OD 0.187	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-26-016	ID 0.084	OD 0.25	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-27-016	ID 0.084	OD 0.312	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-28-016	ID 0.084	OD 0.375	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-29-030	ID 0.093	OD 0.156	Thickness 0.03	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-30-016	ID 0.093	OD 0.187	Thickness 0.016	Material Fiber	ID TOL +-.005	OD TOL +-.005	Quantity
330-31-016	ID 0.093	OD 0.218	Thickness 0.016	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.