Metallics JW1171SS Washers 3/8 X 1-1/2 Fender SS (Jar 100)

It is a 3/8 inch fender washer, so it goes over 3/8 inch bolts, rods, and threaded hangers. The outside diameter is 1-1/2 inches, which spreads the load far wider than a standard 3/8 flat washer and is why it's used over oversized or worn holes.

Solid stainless steel, not a plated carbon washer. That matters if you're mounting outdoors, in a mechanical room, on a rooftop unit, or anywhere there's washdown or condensation, since a zinc-plated washer will rust out first at the bearing face.

That's the main reason to reach for one. With a 1-1/2 inch outside diameter on a 3/8 fastener, the washer bridges thin sheet metal, oversized knockouts, and soft substrates where a standard washer would pull through. Metallics lists the application as electrical, plumbing, heating and air conditioning work, which is exactly that kind of hanging and mounting.

One hundred washers per jar, packaged in a jar rather than a loose bag, so it stays sorted on a service truck or a parts shelf. Total packaged weight is 2.82 lbs.

Yes. The washer is sized to the 3/8 nominal diameter, so it slips over 3/8 threaded rod regardless of thread pitch and seats under the nut to spread load on channel, unistrut, or a trapeze hanger. Stainless construction keeps it from staining the rod or the supported pipe.

Use the standard flat washer when the hole is drilled to size and you're clamping steel to steel. Go to the 1-1/2 inch fender washer when the hole is oversized, slotted, or in a thin or soft material and you need the extra bearing surface to keep the head from pulling through. The tradeoff is footprint, so the fender washer won't fit inside tight bosses, recesses, or narrow channel.

Flat, and specifically a fender washer, which is simply a flat washer with an unusually large outside diameter. It does nothing to resist loosening. If vibration is a concern on the assembly, pair it with a lock washer, a nylon-insert lock nut, or thread locker.