Flat

A flat washer is a thin, typically circular but sometimes square, plate with a hole in the center designed to improve the stress distribution, and to span large clearance holes when using a threaded fastener such as machine screw or a bolt. Flat washers can be used as a spacer and also reduce vibration to keep the fastener assembly secure. Flat washers are offered in different styles and are useful in many different applications. Available and ready-to-ship in a variety of sizes and finishes. Browse our selection of flat washers for your building projects and industrial applications.

Here at BW Industrial Sales, your satisfaction is our number one priority! If you have any questions about countersunk washers or any other manufacturing parts and tooling, please contact our experienced and qualified BW Industrial Sales staff; or call us at 626-358-1836 for an immediate response.


Fender Washers:  A flat washer with significantly more surface area than a USS or SAE washer. They are also made from a thinner gauge metal than most flat washers. Used where an extra wide bearing surface is required. Also offered in a heavier-duty style when a thicker fender washer is needed.

Machine Screw Washer:  The smallest type of flat washer with an outside diameter equal to slightly twice the size of the inside diameter. Designed for use with machine screws in general industrial applications.

SAE Washers:  Similar to a USS washer, but with slightly smaller inside and outside diameters. Most but not all SAE washers are made from thinner materials than USS washers. 

Standard Washers:  A thin flat washer made from 18-8 stainless steel or 316 stainless steel. Designed for use in general industrial applications where parts are subject to corrosion.

Thru-Hardened and Structural Washers:  A flat washer but with tighter tolerances on thickness, manufactured from a higher grade of steel and heat-treated. Designed to perform the same functions as plain washers, but for use specifically with high-strength hardened steel bolts.

Type-B Washers:  The tolerances of the thickness and outside diameter of Type-B washers are tighter than USS and SAE flat washers. Available in narrow, regular, and wide series.

USS Washers:  The most commonly used washer designed to meet the majority of industrial applications in manufacturing, maintenance and repair.