Metallics CSF60F Anchors 1/4 X 4 Fh Ph Blu Conc Scr Cre St-zn (Jar 100)

No separate shield, sleeve, or plastic plug is needed. A concrete screw like the CSF60F cuts its own thread in a pre-drilled hole in concrete, block, or brick, so you drill, blow the hole out, and drive the screw. That is the main reason electricians use them over sleeve anchors for strap and box work: one part, and it can be backed out and reused in a different hole if a layout changes.

A 1/4 inch concrete screw installs in a 3/16 inch hole drilled with a carbide bit in a hammer drill. Use a bit sized for concrete screws, not a worn general-purpose bit, because an oversize hole is the usual reason these spin out instead of holding.

Flat head is the countersinking style, so it pulls down flush when the fixture has a countersunk or chamfered hole. On a flat plate or a strap with a plain drilled hole it will not disappear below the surface, and the head still bears on the material. If you want a bearing head that clamps on top of flat stock, a hex washer head concrete screw is the better pick for that detail.

The CSF60F is carbon steel with blue-coated zinc plating. That coating handles interior work, dry mechanical rooms, and the kind of incidental moisture you get on a job in progress. For permanently wet locations, exterior exposure, or a wet underground vault, step up to a stainless or a heavier corrosion-rated concrete screw rather than zinc-plated carbon steel.

At 4 inches overall, the CSF60F is one of the longer concrete screws in the 1/4 inch size, meant for jobs where the fixture plus any standoff eats up length. Whatever thickness the material you are fastening through adds up to, subtract it from the 4 inches to get your embedment into the concrete, and drill the hole deeper than that embedment so cutting dust has somewhere to go. If you are only fastening a thin strap directly to the slab, a shorter 1/4 inch screw is the cheaper and easier drive.

Metallics catalogs the CSF60F on the electrical side of the house, and the 1/4 inch concrete screw is the standard fastener for mounting strut, conduit straps, box brackets, and panel backing to masonry. Nothing about it limits it to electrical trades, though. The same screw is used by mechanical contractors and maintenance crews anchoring to slab or block.