Metallics JDS177V 14 x 1-1/4 in. 3/8 Indented Hex Head Slotted Sharp Point Tapping Screws - Steel Zinc - Each

Either works. The Metallics JDS177V has a Hex/Slotted drive, so you can run it with a 3/8 in. driver on the hex or back it out with a flat blade in the slot. Head width measures 0.367 to 0.375 in. across the flats and 0.409 in. across the corners, so a 3/8 in. socket or nut setter seats properly. Slot width is 0.064 to 0.075 in. and slot depth 0.083 to 0.101 in., which suits a standard medium flat blade rather than a fine cabinet tip.

It is not self-drilling. The JDS177V is a Type A tapping screw with a gimlet (sharp) point, which means it forms its own thread in a pre-punched or pre-drilled hole in thin sheet metal but will not cut through stock on its own. For heavier gauge steel you want a self-drilling (Type TEK style) screw instead.

They are flagged compliant for both Buy American and ARRA. Country of origin is listed as multiple, so if your specification requires a single documented origin for each lot, confirm the origin on the jar you receive. Dimensionally they are built to ASME B18.6.3-2010 with ASME B18.6.4 threads.

Threads run 10 per inch to ASME B18.6.4, the Type A sheet metal thread form. That coarse spacing is meant for thin sheet steel, electrical enclosures, duct and similar, and it also bites fine in wood or composite board where a coarse single lead thread is wanted. Overall length is 1-1/4 in. in a #14 diameter.

Yes, there is an integral washer face under the indented hex head. Washer OD runs 0.480 to 0.520 in. with a thickness of 0.030 to 0.050 in., so the bearing surface is wider than the 3/8 in. head and spreads load on sheet metal without a separate loose washer. Head height is 0.172 to 0.19 in.

These ship in a jar of 500 count, and 500 is the order minimum, so it is bought by the full jar rather than loose by the piece. The jar weighs 8.5 lbs.

Torsional strength is 125 lb-in minimum, with case hardness of Rockwell C28-38 from AISI 1016-1024 steel. That is enough to form threads in sheet metal under power, but an impact driver will exceed 125 lb-in easily, so set the clutch or finish by hand to avoid shearing heads. Heat treated case with a softer core is normal for a Type A tapping screw.

The JDS177V is steel with a zinc finish, which is a plated coating for indoor and dry-location corrosion resistance. For exterior exposure, wet locations or treated lumber contact, go to a stainless or hot dip galvanized fastener instead; plain zinc plating will eventually rust in those conditions.

This is an electrical-trade fastener: a #14 x 1-1/4 in. Type A tapping screw with a 3/8 in. hex head, used for mounting devices, straps, boxes, covers and supports into pre-punched sheet metal, and anywhere a wrenchable head is faster than a bit. The hex head lets you run a long run of them with a nut setter in a drill, and the slot gives you a backup if the hex rounds.