Metallics JLWC175 Washer 1/2 Split Lockwshr Cu (Jar 100)

The JLWC175 is a 1/2 inch split lock washer in copper. The 1/2 designation refers to the bolt or stud diameter it fits, so it goes over 1/2 inch threaded hardware, not a 1/2 inch hole measured across the washer.

Each jar holds 100 of the 1/2 inch copper split lock washers. The jar pack is the standard way these ship, which suits a service truck or a shop bin rather than a single-piece pull.

Copper is used on grounding and bonding hardware so the washer matches the copper conductor and copper or bronze lugs it sits against, avoiding a dissimilar-metal joint that can corrode and raise resistance over time. The JLWC175 is a copper split lock washer sold as electrical fastening hardware, which is where that matters most. For general structural bolting with no electrical path, a plated steel lock washer is the usual choice.

It is a split lock washer, the helical type with a gap that compresses under the nut and bears against it to resist loosening from vibration. If you need load spreading over a soft surface or a larger bearing area, that is a flat washer and this is not it. Many ground bar and lug connections use both, a flat under the split lock.