40545 USS 1/2" Flat Washers Box/100

Overview

The 40545 USS 1/2" Flat Washers (03830) are designed for load distribution in threaded fastener assemblies. Manufactured by Midwest Fastener Corp, these USS-series flat washers are sold in a box of 100 pieces, making them suited for production, maintenance, and construction applications requiring consistent hardware supply.

Technical Features

• USS Series body geometry: features a larger outside diameter compared to SAE washers, providing a wider bearing surface to distribute fastener load across a greater area and reduce material pull-through.
• Flat, thin plate profile: seats flush beneath a threaded fastener head or nut, ensuring even load transfer without adding unnecessary stack height to the assembly.
• Center hole sized for 1/2" fasteners: provides a direct fit for standard 1/2" bolts and screws, eliminating the need for sizing adjustments on the job site.
• Box quantity of 100 pieces: supports bulk fastening tasks and reduces per-unit cost for repetitive or high-volume assembly work.

USS vs. SAE — Key Distinction

USS flat washers feature a larger, wider outer diameter than SAE flat washers. SAE washers are machined to a tighter specification with a smaller outside diameter. USS washers are the preferred choice where a broader load-bearing footprint is required or where the mating surface material is softer and more susceptible to indentation under clamp load.

Applications

• General construction and structural bolted connections requiring load distribution.
• Wood framing and decking assemblies where fastener pull-through into softer materials is a concern.
• Mechanical and equipment assembly using 1/2" threaded fasteners.
• Maintenance and repair operations where a standard USS-specification washer is specified.