Metallics JDS178 14 x 1-1/2 in. 3/8 Indented Hex Head Slotted Sharp Point Tapping Screws - Steel Zinc - Each

The JDS178 is a Type A tapping screw with a gimlet (sharp) point, which is the point style meant to start in a pre-punched or pre-drilled hole in thin sheet metal and form its own thread as it drives. Metallics lists its field application as light metal assembly such as electrical outlets, framing and other sheet metal. For thicker steel or structural thickness, a Type A sharp point is the wrong choice.

Either. The head is an indented hex with a slot cut across it, so a 3/8 inch nut driver or a flat blade both work. Across the flats the head measures 0.367 to 0.375 in., across corners 0.409 in., so a 3/8 driver seats properly. The slot runs 0.064 to 0.075 in. wide and 0.083 to 0.101 in. deep, which suits a standard cabinet-tip flat blade rather than a wide blade.

No. Metallics lists the JDS178 as not Buy American compliant and not ARRA compliant, with country of origin shown as multiple. On a federally funded project with domestic sourcing requirements, you need a domestically manufactured tapping screw instead.

They are a #14 diameter screw, 1-1/2 inches long, with 10 threads per inch. Thread form follows ASME B18.6.4 and the head dimensions follow ASME B18.6.3-2010.

Yes, the head carries a washer face with an outside diameter of 0.480 to 0.520 in. and a thickness of 0.030 to 0.050 in. That spreads the clamp load wider than the 3/8 in. hex itself, which is what keeps the screw from pulling through thin sheet. Overall head height is 0.172 to 0.19 in.

Torsional strength is rated at 125 lb-in minimum, and the screws are case hardened to Rockwell C28-38 from AISI 1016-1024 steel. That is enough to thread-form in light sheet metal, but a high-torque impact driver can still exceed it, so set the clutch or drive on a lower speed setting.

The JDS178 is steel with a zinc finish. Zinc plating is an indoor/dry-location coating; it handles incidental moisture but it is not a marine or sustained-wet finish. For exterior or wet locations, step up to a stainless or hot-dip galvanized fastener instead.

They ship in a jar of 100, and 100 is the order minimum. Package weight is 1.96 lbs. Metallics notes other sizes and quantities are available by request.

For a device box flange or outlet mounting, 1-1/2 inches of #14 is a long fastener and it will protrude well past thin sheet. The JDS178 suits thicker build-ups, framing members, and anchoring into wood or studs behind light metal, where you want length for grip. If you only need to join two sheet metal layers, order a shorter length in the same JDS indented hex slotted series.