Metallics JSSW121D Washers 1/4 Flat SS (Jar 100)

The JSSW121D is a 1/4 inch flat washer, so it is sized for 1/4-20 and 1/4-28 bolts, screws and threaded rod. Order by bolt diameter, not by hole diameter, since a 1/4 inch flat washer's hole runs slightly oversize to clear the thread.

Solid stainless steel, not a zinc or galvanized coating over carbon steel. That matters for outdoor strut runs, rooftop equipment, damp mechanical rooms and coastal sites, where a plated washer gives up its coating at the edges and starts bleeding rust onto the fixture.

100 pieces, packed in a jar rather than a loose bag. The jar is the practical part for a service van or a shop bench: it reseals, it stacks, and you can pour out a handful without the rest ending up in the bottom of the bin.

Mechanically yes, and it is done all the time on strut and channel work. Keep in mind that stainless against zinc-coated steel in a wet location sets up a dissimilar metal couple, so for exterior or washdown installations the cleaner practice is to keep the whole assembly stainless. The JSSW121D is solid stainless, so pairing it with stainless 1/4-20 bolts and nuts gives you a consistent run.

The JSSW121D is built to the ANSI dimensional standard for flat washers, so the outside diameter, hole and thickness match other ANSI 1/4 inch flat washers already on the job. You can top up a bin without the new ones sitting proud or overhanging a strut slot.

It spreads the clamping load of the bolt or nut over a wider area so the head does not dig into sheet metal, a strut flange, an enclosure wall or a ground bar seat, and it gives a smooth bearing surface so the fastener turns without chewing the material. The JSSW121D is the 1/4 inch flat version, used under 1/4 inch bolt heads and nuts. If you also need the joint to resist loosening under vibration, add a lock washer or a nylon insert nut, since a plain flat washer does not provide that by itself.