Hillman Fasteners 300030 Split Lock Washer 1/2 in 50 Pack

Product Description

The HILLMAN FASTENERS 300030 is a split lock washer designed to resist fastener loosening caused by vibration and torque relaxation. Sold in a 50-piece pack, each washer measures 1/2 inch and is made from zinc plated steel for basic corrosion resistance in general-purpose applications. The split ring design bites into both the fastener bearing surface and the mating material when the fastener is driven to full torque, creating mechanical resistance to back-out. These washers are a standard component in mechanical assemblies across HVAC equipment, plumbing fixtures, electrical enclosures, and structural hardware installations.

This washer is suited for residential and light commercial applications where a 1/2 inch fastener requires positive locking without an adhesive or prevailing-torque nut. Typical uses include equipment mounting, panel assembly, pipe hanger hardware, and general mechanical fastening. The zinc plating provides adequate protection for indoor and sheltered outdoor environments. Electricians, HVAC technicians, plumbers, and general contractors routinely stock this size for service and new-installation work.

Key Features

• Split ring design creates mechanical resistance to vibration-induced loosening
• 1/2 inch bore fits standard 1/2 inch fasteners
• Zinc plated steel construction for corrosion resistance in general-purpose environments
• 50-piece pack suitable for service stock or small-batch installation work
• Compatible with standard hex bolts, cap screws, and machine screws of matching diameter

Compatibility

Designed as a standard OEM-style split lock washer for use with 1/2 inch diameter fasteners in general mechanical, HVAC, plumbing, and electrical applications.

Installation Notes

Install the split lock washer between the fastener head or nut and the mating surface before driving to final torque. Ensure the fastener and washer bore diameters match before assembly. Follow applicable codes such as NEC or IFGC for fastener requirements in electrical or gas-related installations. Do not reuse lock washers that have been fully compressed flat, as the locking function is reduced after initial set.