Metallics JSWBR516 Washers 5/16 Flat Br (Jar 100)

The JSWBR516 is a 5/16 inch flat washer, so it is sized for 5/16 inch bolts, screws, and threaded rod. It is solid brass, which is what you want when you are bolting to brass or bronze hardware or need to avoid the galvanic pairing you get from plain steel against copper-alloy parts.

One hundred 5/16 inch brass flat washers, packed in a jar rather than a bag. The jar is the orderable unit, so it suits a service van or a shop bin where you are pulling a handful at a time.

Brass is the usual pick where you are landing on copper or brass grounding hardware, since a brass washer with a copper conductor avoids the dissimilar-metal corrosion you get with plain steel. The JSWBR516 is solid brass in the 5/16 inch size, which matches common ground bus and lug hardware. It is a flat washer only, so it spreads load and protects the surface, it does not provide any locking function.

No. The JSWBR516 is a flat washer, so it distributes clamping load across the material and keeps the nut from digging into the surface. If you need the fastener to resist loosening from vibration, you want a split-ring lock washer or a serrated washer in addition, not this one.

The jar weighs 0.72 lbs and measures 3 x 2.7 x 3 inches, small enough to sit in a van drawer or a parts bin without repacking.

Country of origin is China. That matters on public and institutional work where a Buy American or domestic-sourcing clause applies, so check the spec on the job before committing to these.