Metallics JDS161M 6 x 1/2 in. 1/4 Indented Hex Head Slotted Sharp Point Tapping Screws - Steel Zinc - Each

Either. The head is an indented hex with a slot, so a 1/4 inch nut driver works and a flat blade fits the slot. Head width across the flats is 0.244 to 0.25 inch and across corners 0.272 inch, so a 1/4 inch driver is the right size. The slot is 0.039 to 0.048 inch wide and 0.033 to 0.046 inch deep, which suits a small cabinet-tip blade. Electricians generally run these with a nut driver and keep the slot as a backup when the hex gets stripped or access is tight.

The JDS161M is zinc plated carbon steel, which is an indoor and dry-location finish. It handles incidental moisture but will rust in sustained wet, wash-down, or coastal exposure. For exterior enclosures, mechanical rooms with standing humidity, or anywhere a NEMA 3R/4 box lives outside, specify a stainless sheet metal screw instead.

The Metallics JDS161M is a Type A tapping screw with a gimlet (sharp) point, so it forms its own thread in thin sheet metal, but it does not drill its own hole. You need a pilot hole or an existing knockout. For thicker steel or where you want one-step drilling and tapping, a self-drilling (TEK-style) screw is the better choice. Type A screws are standard for sheet metal work like fastening into light-gauge enclosures and boxes.

It is a #6 diameter by 1/2 inch long screw with 18 threads per inch, built to the ASME B18.6.4 thread standard and ASME B18.6.3-2010 for dimensions. That thread count is the standard Type A pitch for a #6, so it will match the existing #6 sheet metal screws in most panel and box work.

Torsional strength is rated at 24 lb-in minimum and the screws are case hardened to Rockwell C28-38 from AISI 1016-1024 steel. That is the normal spec band for a #6 Type A screw. Practical takeaway: drive these with a hand driver or a clutched drill at low torque. An impact driver on a #6 will twist the head off well before the fastener is seated.

Yes, the head has an integral washer face. Washer outside diameter runs 0.302 to 0.328 inch with a thickness of 0.015 to 0.025 inch, and head height is 0.08 to 0.093 inch. That bearing surface spreads the clamp load on thin sheet so you are less likely to dish the metal, and it covers a slightly oversized hole. No separate washer is needed.

Metallics lists the JDS161M as both ARRA compliant and Buy American compliant. Country of origin is recorded as multiple, so if your contract requires a single named origin on the submittal, confirm the origin on the specific lot you receive.

At 1/2 inch of overall length with a gimlet point, the usable thread engagement is short, so this size is meant for fastening light-gauge sheet to light-gauge sheet, device plates, covers, and strapping on thin material. If you are going through insulation, a spacer, or stacked flanges, step up to a longer length in the same JDS series rather than relying on the point to find metal.

They ship in a jar of 1,000 pieces, which is the order minimum, at 2.43 lbs. Other sizes and quantities can be had by request.