Metallics TS788 Anchors 7/8 x 8 Wdg St-zn (Box 5)

Wedge anchors are drilled with a carbide bit matching the anchor's nominal diameter, so a 7/8 inch anchor needs a 7/8 inch hole in the concrete, drilled deeper than the embedment you need so dust and cuttings have somewhere to go. The TS788 is 8 inches overall, so the portion above the surface (plate thickness plus nut and washer) comes out of that 8 inches when you set your embedment.

No. Wedge anchors are for solid, poured concrete only. Hollow block, brick, mortar joints, and drywall will not develop the expansion a wedge anchor relies on. For hollow base material you want a sleeve anchor, a toggle, or an epoxy/screen tube system instead. The 8 inch length on the TS788 also assumes a thick concrete section, not a thin topping slab.

A wedge anchor of this type is supplied as a complete assembly: the threaded stud with the expansion clip, plus the nut and washer already on the threaded end. You drive it through the fixture into the drilled hole and tighten the nut to set the wedge, so no separate hardware purchase is needed for the anchor itself.

Zinc plated carbon steel is a dry-to-mildly-damp interior finish. It will hold up in a covered mechanical room or interior slab work, but on an exposed exterior pad, a pool deck, a coastal site, or anywhere it sees chlorides, plated steel corrodes and a stainless wedge anchor is the right call. The TS788 is the zinc plated steel version.

A 7/8 inch by 8 inch wedge anchor is heavy-anchor territory: equipment pads, switchgear and transformer bases, large strut and trapeze supports, and machine or rack base plates bolted to a concrete slab. Metallics carries it as electrical fastening stock, but the anchor itself is generic structural concrete anchorage and gets used the same way by general and mechanical trades.