Hillman Fasteners 270009 5/16 Flat Washer Zinc Steel 5 Lb

Product Description

The HILLMAN FASTENERS 270009 is a bulk pack of 5/16-inch zinc-plated steel flat washers in the USS wide pattern. Each pack contains approximately 435 pieces and weighs 5 pounds, making it a practical stock item for contractors, service techs, and maintenance crews who burn through fastener hardware regularly. The USS wide pattern provides a larger outer diameter than standard SAE washers, distributing load more effectively across softer or larger-clearance surfaces. Zinc plating delivers corrosion resistance suitable for general indoor and sheltered outdoor applications.

These flat washers are used across plumbing, HVAC, electrical, and general mechanical assembly wherever a 5/16-inch fastener needs a bearing surface or load-spreading washer. The wide USS pattern is commonly specified when working with oversized holes, softer base materials, or anywhere a standard washer footprint is insufficient. The bulk 5-pound pack format is suited for shop stocking, service vans, or job-site bins where individual packaging is impractical.

Key Features

• USS wide pattern outer diameter for increased load distribution
• Zinc-plated steel construction for corrosion resistance in general-duty applications
• Approximately 435 pieces per 5-pound pack
• 5/16-inch nominal size fits standard 5/16-inch bolts and screws
• Bulk pack format reduces per-piece cost for high-volume use

Compatibility

Designed for use with 5/16-inch diameter fasteners in general mechanical, HVAC, plumbing, and electrical assembly applications requiring a USS wide-pattern flat washer.

Installation Notes

Flat washers are installed by any trade working with bolted connections. Always ensure the washer inner diameter is matched to the fastener shank diameter before assembly. Follow applicable codes such as NEC, IPC, or IFGC when washers are used as part of a code-governed fastened connection. Zinc-plated washers are not rated for direct contact with pressure-treated lumber or highly corrosive environments without additional protection.