Metallics JTS303 Anchors 3/8 X 3 Wedge Ancr St-zn (Jar 100), 100 Pack

That's exactly what it's for. The JTS303 is a 3/8 inch steel wedge anchor carried as electrical fastening hardware, the type used to hang strut channel, conduit clamps, junction boxes and enclosure backplates on poured concrete. Wedge anchors are for solid concrete only, not hollow block, brick or grouted CMU.

A 3/8 inch wedge anchor is set in a 3/8 inch hole drilled with a carbide hammer-drill bit. The anchor diameter and the bit diameter match on wedge anchors, which is what makes them fast on a big install: drill 3/8, blow the hole clean, drive the anchor through the fixture, tighten the nut to expand the clip.

It's a steel anchor with zinc plating. Zinc plating handles dry interior work and normally protected locations fine. For exterior exposure, wet wells, coastal air or anywhere it sees standing water, spec a stainless or hot-dip galvanized wedge anchor instead, since plated zinc is a sacrificial coating and will eventually rust through.

No. Wedge anchors ship as a complete assembly, with the nut and washer already on the threaded end from the factory. The nut is what pulls the cone up into the expansion clip when you torque it, so it's part of the anchor, not an add-on. All you supply is the hammer drill, the matching bit and a wrench.

No. Once the cone draws the clip into the hole wall, a wedge anchor is permanent. You can back the nut off and take the fixture away, but the anchor body stays in the concrete, and it can't be pulled and re-driven in a new hole. For work that has to come apart and go back, use a drop-in anchor with a machine screw or a threaded insert instead. Ordering 100 to a jar makes sense here because you'll consume them on the first set.

Order it as Metallics JTS303. That number covers the 3/8 by 3 inch steel zinc-plated wedge anchor in the 100-count jar, and it's the only configuration that part number carries, so there's no length or finish suffix to specify.