Metallics SLWK1 Washers Split Lock Kit SS (Trey 400)

The SLWK1 assortment covers bolt sizes #8 through 1/2 inch, so it handles everything from small machine screws on device straps up to 1/2 inch threaded rod and anchor hardware. That range is what makes it a single-tray solution for most electrical and mechanical rough-in work instead of stocking individual boxes per size.

Stainless steel throughout. That matters if you're working outdoors, in damp mechanical rooms, on rooftop equipment, or anywhere a zinc-plated washer would bloom rust and seize the fastener later. For a maintenance crew standardizing on one assortment, stainless covers both interior and exterior openings without a second kit.

425 assorted pieces come in the tray, spread across the #8 to 1/2 inch size range. It ships as a compartmented tray rather than loose bulk, so sizes stay separated on the truck or the shop shelf.

The tray measures 8 x 4.62 x 1.25 inches, which slides into most van shelving cubbies, tool bag pockets, and standard parts-organizer slots. It's a flat tray, not a deep bin, so it stacks with other Metallics assortment trays.

Split lock washers work by digging into the nut face and the bearing surface under spring tension, which resists loosening from vibration. Use them where equipment vibrates: motor mounts, rooftop units, panel and strut connections. A flat washer only spreads load and does nothing against vibration, and it's often used under the split lock rather than instead of it. A nylon insert lock nut is the alternative when you can't get a hardened bearing surface or the joint gets taken apart repeatedly. The SLWK1 tray is strictly split lock washers, so pair it with flat washers and nuts you already stock.

It's built for the electrical, plumbing, heating and air conditioning trades, so a mechanical contractor or an MRO crew gets the same use out of it as an electrician. Anywhere you're landing strut clamps, hangers, equipment feet, or panel hardware in the #8 to 1/2 inch range, the tray covers it.

The SLWK1 washers are stainless steel, and mixing stainless against zinc-plated or galvanized fasteners in a wet or exterior location sets up galvanic corrosion at the contact point, with the zinc coating sacrificing first. Indoors and dry, it's a non-issue. Outdoors, match the washer to the bolt material.

Order it as Metallics SLWK1. That single part number covers the complete 425-piece stainless split lock washer tray; there are no size or finish variations to specify.