Metallics JSWHH75 Washer 3/8 Flat SAE Wshr Extra Hvy Dt (Jar 100)

The JSWHH75 is a 3/8 inch SAE flat washer, so it is sized for 3/8 inch bolts, screws, and threaded rod. SAE pattern means a smaller outside diameter and smaller hole than a USS washer of the same nominal size, so it sits tighter to the fastener head and is the one to use when the hole in the material is close to the bolt diameter.

Extra heavy duty means more thickness and more material under the nut than a standard flat washer of the same 3/8 inch size. That matters when you are bolting through strut, sheet metal, or soft material and the standard washer would dish or pull through under torque. The JSWHH75 is the extra heavy duty 3/8 SAE pattern, so use it where the joint gets torqued hard or carries vibration; a standard flat washer is enough for light trim and cover plate work.

Yes. The JSWHH75 takes 3/8 inch threaded rod, which is the common hanger rod size for conduit racks, strut trapeze, and pipe hangers. Pair it with a 3/8 nut on each side of the strut or fitting. If the slot or hole you are spanning is wide, the SAE pattern may not bridge it, and a USS pattern washer in 3/8 gives you the larger outside diameter for that.

They are catalogued by Metallics as electrical supply fasteners, which is where they get used most: strut and channel mounting, hanging rod, panel and enclosure bolting, and ground bar hardware. Nothing about a 3/8 SAE flat washer limits it to electrical work, so the same jar serves mechanical and general construction bolting at the same bolt size.