Metallics DS181B 10 x 3/4 in. 5/16 Indented Hex Head Slotted Sharp Point Tapping Screws - Steel Zinc - Each

The Metallics DS181B is a Type A tapping screw, meaning it has a gimlet (sharp) point and a coarse 12 threads per inch, so it forms its own thread as it drives. That combination is meant for thin sheet metal, sheet metal boxes and enclosures, and similar light-gauge work where you can start the screw in a pilot hole without a pre-tapped thread. Steel with a zinc finish on the outside.

Either. The DS181B has a dual drive: an indented hex head measuring 0.305 to 0.312 inch across the flats, which is the 5/16 nut driver or socket size, plus a slot 0.050 to 0.060 inch wide and 0.057 to 0.072 inch deep for a flat blade. Crews usually run them with a 5/16 magnetic nut setter and keep the slot as the backup for tight spots or removal.

Yes, the DS181B is flagged compliant for both Buy American and ARRA. Country of origin is listed as multiple, so if your submittal package needs a single named origin on the certification, that is worth confirming with the mill cert for the lot you receive.

It does. The head carries an integral washer with an outside diameter of 0.384 to 0.414 inch and a washer thickness of 0.019 to 0.031 inch, head height runs 0.105 to 0.120 inch. The washer face spreads load on thin sheet so you are less likely to dimple or pull through light-gauge metal, and no separate washer is needed.

Dimensions are to ASME B18.6.3-2010 and the threads to ASME B18.6.4, with steel to AISI 1016 through 1024. Case hardness is Rockwell C28-38 and minimum torsional strength is 48 lb-in. Note that dimensions for the #9 diameter fall outside ASME B18.6.4.

The DS181B ships as a box with an order minimum of 3,000 pieces, the standard bulk pack for this size. Metallics does offer other sizes and quantities on request if 3,000 of a #10 x 3/4 is more than the job needs.

The finish here is zinc over steel, which is a standard indoor and protected-location plating. It handles normal dry interior electrical work fine, but for exterior, wet, or corrosive locations zinc plating is not the right call, you want stainless or a hot dip coated fastener in that case.

Minimum torsional strength on these is 48 lb-in with a case hardness of Rockwell C28-38. That is a #10 sheet metal screw, not a structural fastener, so run it with a clutch or a low-torque setting. Most snapped heads on this size come from over-driving into heavier gauge than the sharp gimlet point was meant for.

A full box of the DS181B weighs 17.87 lbs and measures 7.25 by 6.25 by 6 inches, which is what 3,000 pieces of a #10 x 3/4 steel screw comes to. Easy enough for one hand on a cart, but worth knowing if you are stocking a van shelf or a stockroom bin.