Metallics DS184M 10 x 1-1/2 in. 5/16 Indented Hex Head Slotted Sharp Point Tapping Screws - Steel Zinc - Each

The Metallics DS184M is a Type A tapping screw with a gimlet (sharp) point, 12 threads per inch. The sharp point starts in a pilot hole in thin sheet metal and forms its own thread, but it does not drill. You still need a pre-punched or drilled pilot hole. If you want to go straight into the metal with no pilot, you need a self-drilling (Teks style) screw instead. Metallics lists this one for the electrical, plumbing, heating and air conditioning trades.

No. The DS184M ships as a box with an order minimum of 1000 pieces. Metallics notes that other sizes and quantities are available by request, so if you need a different length or diameter in a smaller count that is the route.

Metallics flags the DS184M as compliant for both ARRA and Buy American. Country of origin is listed as multiple, so if your contract requires a single documented origin, request the certification for the specific lot you are buying.

Two options on the same screw. The indented hex head measures 0.305 to 0.312 in. across the flats, so a 5/16 in. hex driver or nut setter fits it, and 0.34 in. across the corners. It is also slotted (slot width 0.05 to 0.06 in., depth 0.057 to 0.072 in.), so a flat blade works when you cannot get a nut setter in. Head height runs 0.105 to 0.12 in.

Yes, the indented hex head carries an integral washer face with an outside diameter of 0.384 to 0.414 in. and a thickness of 0.019 to 0.031 in. That spreads the bearing load on sheet metal and on strap or hanger material, so you do not need a separate washer for most electrical and HVAC fastening.

The DS184M is rated to 48 lb-in minimum torsional strength and is heat treated to Rockwell C28-38, made from AISI 1016-1024 steel. That is enough for normal power driving into sheet metal, but an impact driver will overrun 48 lb-in easily once the head seats. Use a clutch or set the driver low and stop on seat rather than driving to stall.

The screw is steel with a zinc finish. Zinc plating is a mild corrosion coating meant for dry interior and protected work, which is what the electrical, plumbing and HVAC applications it is listed for usually are. For sustained wet exposure, coastal air, or pressure treated contact, specify stainless or a coated exterior fastener instead.

Head dimensions follow ASME B18.6.3-2010 and the thread follows ASME B18.6.4, which is the tapping screw thread standard. One exception worth knowing for a spec submittal: dimensions for #9 diameter screws in this family are independent of ASME B18.6.4. This item is the #10 diameter, 1-1/2 in. length.

The boxed 1000-count comes in at 9.68 lbs, with carton dimensions of 7.25 x 6.75 x 3.25 in. Useful if you are staging material by van load or figuring freight on a multi-box order.

Order Metallics part DS184M, from the JDS series. That number covers the #10 x 1-1/2 in. indented hex head slotted sharp point Type A tapping screw in steel zinc.