Rectangular OD Washers - Custom Flat Washers with Rectangular Profile

Rectangular OD Washer Frequently Asked Questions

Below are answers to some of the most common questions about rectangular OD washers.

What are rectangular OD washers?
Rectangular OD washers feature a square or rectangular outer profile with a round inner bore. Like standard flat washers, they distribute load, protect bearing surfaces, and add spacing in fastener assemblies. The rectangular outer profile provides a larger and more stable bearing footprint than a round washer, making them well suited for slotted holes, structural fastening, and applications where the washer must be retained against rotation or movement. Superior Washer manufactures rectangular OD washers in a comprehensive range of sizes and materials.

What is the difference between rectangular OD and square OD washers?
Square OD washers have equal length and width outer dimensions, creating a true square profile. Rectangular OD washers have different length and width dimensions, creating a non-square rectangular outer profile. Both provide larger bearing surfaces than round washers and are used in structural and slotted-hole fastening applications. Superior Washer manufactures both types to custom specifications.

What applications use rectangular OD washers?
Rectangular OD washers are used in timber construction, structural steel connections, machinery base mounting, electrical panel fabrication, and any application requiring a large, stable bearing surface under a fastener head or nut. They are also used in slotted hole applications where the elongated washer spans the slot to prevent pull-through.

What materials are rectangular OD washers available in?
Rectangular OD washers are produced in low carbon steel, stainless steel, brass, aluminum, and other materials on request. Contact us to specify your required material and dimensions.

Can you produce custom rectangular OD washers?
Yes. We manufacture custom rectangular OD washers to your exact length, width, ID, and thickness specifications. Our in-house die shop allows us to produce non-catalog shapes efficiently. Contact us via the Quick Quote form or call NY (631) 273-8282 or SC (803) 366-3250.

Are your rectangular OD washers made in the USA?
Yes. All rectangular OD washers are manufactured in the United States under our ISO 9001:2015 certified Quality Management System at our Hauppauge, NY and Rock Hill, SC facilities.

Need a round profile instead? Browse the full flat washers catalog to see all shapes and materials available.