Value Collection SIWIS031HDUSA-100BX Lock Washer 5/16 in

Product Description

The VALUE COLLECTION SIWIS031HDUSA-100BX is a heavy-duty internal tooth lock washer designed for use with 5/16-inch screws and fasteners. Made from Grade 2 spring steel with an uncoated finish, this washer uses internal serrated teeth that bite into the mating surface and fastener head to resist loosening under vibration and torque. The inside diameter measures 0.332 inches and the outside diameter measures 0.607 inches, with a thickness of 0.045 inches. It is sold in a minimum order quantity of 100 pieces, making it well suited for production, maintenance, and bulk service work. HVAC technicians, electricians, plumbers, and general mechanical trades use this type of washer wherever fastener retention under vibration is required.

Internal tooth lock washers in this size range are commonly used in residential and light commercial mechanical assemblies, electrical panel and enclosure work, equipment mounting, and general structural fastening. The internal tooth design keeps the washer centered on the fastener shank during installation, reducing the chance of misalignment in tight or recessed bolt patterns. This washer conforms to DIN 6797 and DIN 6798 dimensional standards, making it interchangeable with components specified to those standards in mechanical and electrical trade applications.

Key Features

• Internal serrated tooth design centers on fastener shank and resists rotational loosening under vibration
• Grade 2 spring steel construction provides reliable elasticity and holding force across standard mechanical applications
• 0.332-inch inside diameter fits standard 5/16-inch screw and bolt shanks
• 0.607-inch outside diameter suits typical recessed and flush fastener installations
• Uncoated finish — suitable for dry indoor environments and applications where post-installation coating is applied
• Conforms to DIN 6797 and DIN 6798 standards
• Heavy-duty designation; sold in 100-piece minimum quantity increments

Compatibility

Designed as an OEM-style replacement and general-use internal tooth lock washer for 5/16-inch fastener applications conforming to DIN 6797 and DIN 6798 dimensional standards.

Installation Notes

Install this washer between the fastener head and the mating surface with the teeth facing the surface to be gripped. Ensure the mating surface is clean and free of debris before seating the washer. Do not reuse lock washers after removal, as the teeth lose retention effectiveness once deformed. Applicable installation work should follow NEC, IFGC, or IPC guidelines as appropriate to the trade and system being serviced.