Metallics TXV1278Z Screws 12-24 x 7/8 HWH Unslot #4 Tek (100 pcs)

The TXV1278Z is a 12-24 x 7/8 inch screw. The 12-24 thread is the machine-screw thread used with threaded electrical and strut hardware, so it will run into a 12-24 tapped hole as well as self-drill its own in sheet steel.

No. The #4 point on this screw is a self-drilling drill point, so it cuts its own hole and taps the thread in one pass through sheet steel. That is what separates a Tek screw from a plain self-tapping screw, which needs a pre-drilled hole.

Yes, that is the normal use for this screw. The self-drilling #4 point goes straight through metal stud or sheet steel without a pilot hole, the hex washer head gives a broad bearing surface so it does not pull through a thin bracket or a box ear, and the 7/8 inch length leaves enough thread past the steel to hold. For wood framing or anchoring into masonry, use a wood screw or a masonry anchor instead; a Tek point is meant for metal.

A hex nut driver. The head is a hex washer head with no slot (HWH Unslot), so there is no Phillips or slotted recess to fall back on, it drives only from the hex. Keep a nut driver on the drill rather than a bit holder.

The TXV1278Z carries a zinc plated finish, which is a general purpose indoor and dry-location coating. For sustained outdoor exposure or damp environments, step up to a hot dip galvanized or stainless fastener instead.

Each pack of the 12-24 x 7/8 hex washer head Tek screw holds 100 pieces, which is the usual box count for running strut, box mounting, and sheet metal fastening on a job without breaking down a bulk carton.