Metallics FSCS10 Anchor 1/4 x 1-1/4 Flat Hd Square Drive Concrete Screw Nail Point USA (100pcs)

The FSCS10 is a 1/4 inch diameter concrete screw, so it installs in a 3/16 inch hole drilled with a carbide bit, which is the standard pilot for 1/4 inch concrete screws. Drill at least 1/4 inch deeper than the embedment and blow the dust out before driving, or the screw will bind before it seats.

Dimensionally it matches that common size: 1/4 inch diameter, 1-1/4 inch length, flat countersink head. The drive is square rather than the Phillips head many crews are used to, so grab a #3 square bit before you start. It installs in the same 3/16 inch pilot hole.

It is a square drive flat head, so you need a square (Robertson) bit, not Phillips or hex. For a 1/4 inch concrete screw that is a #3 square bit. An impact-rated bit is worth using here, since driving into masonry chews up standard bits fast.

The FSCS10 has a flat head, which is the countersink style: in a countersunk hole it sits flush, and against a flat strap or clamp it seats low and tight without the raised profile of a hex washer head. If you need a bearing surface against a sheet metal flange or you plan to run it with a socket, a hex head concrete screw is the better pick.

The nail point is a sharpened lead tip that lets the screw find the hole and start cutting threads without walking off the mark, which matters when you are working overhead on a deck or driving a long run of conduit straps one-handed. It does not let you hammer it in. The FSCS10 still needs a pre-drilled hole in the concrete.

Concrete screws in this 1/4 inch size are used in poured concrete, solid and hollow CMU block, and brick, provided you drill with a carbide bit and hit solid material rather than a mortar joint or the hollow cell wall. In hollow block, land the screw in the face shell web. The FSCS10 is not a drywall or wood fastener; it needs masonry to cut threads into.

No plug, shield, or expansion sleeve is involved. The FSCS10 cuts its own thread directly into the drilled hole in the masonry, so the only consumables on the job are the screws and a 3/16 inch carbide bit. That also means it can be backed out and the fixture removed without leaving an anchor body buried in the slab.

Boxed 100 pieces per unit under part number FSCS10, and they are made in the USA. For a standard conduit strap layout that covers a sizeable run, which is why this quantity is the usual pull for electrical rough-in rather than a 25-count card.