Metallics JDSP185 10 x 2 in. 5/16 Hex Head Phillips Sharp Point Tapping Screws - Steel Zinc - Each

Two options on the same screw. The head is a hex washer head measuring 0.305 to 0.312 in. across, so a 5/16 nut driver or socket seats on it, and the same head carries a Phillips recess sized 0.178 in. taking a #2 Phillips bit. Head height runs 0.105 to 0.12 in. Crews usually run the nut driver for speed and switch to the #2 bit in tight spots where a socket will not clear.

Not in sheet metal or wood-type substrates. The JDSP185 is a Type A tapping screw with a gimlet (sharp) point, which pierces and forms its own thread in thin sheet, so no pilot hole is required. It is not a self-drilling point though, so for thicker steel plate you still drill a pilot. Thread count is 12 threads per inch over a 2 in. length.

It is integral. The hex head is formed with a washer face measuring 0.384 to 0.414 in. outside diameter and 0.019 to 0.031 in. thick, so it spreads the bearing load on sheet metal or a box flange without a loose washer. No separate washer to order or drop off a ladder.

The JDSP185 carries a 48 lb-in minimum torsional strength with a case hardness of Rockwell C28-38, which is the normal heat-treated range for a Type A tapping screw. That is plenty for hand-driving or a clutched screwgun. On an impact driver, dial the torque back, since a #10 sheet metal screw will twist off before the hardened point gives up.

Zinc plating over steel is a mild indoor corrosion coating, not a weather finish. The JDSP185 is steel with a zinc finish, which suits dry interior electrical work, panel and box mounting, and interior framing. For exterior, damp, or coastal exposure, specify a stainless or hot-dip galvanized fastener instead.

They ship 100 to a jar, and 100 count is the order minimum, so a single buy line gets you a full jar rather than loose pieces. Packed weight is 1.3 lbs.

The JDSP185 is flagged compliant for both ARRA and Buy American, with country of origin China. On federally funded work, confirm which clause your contract invokes, since some specs require domestic melt and manufacture rather than the compliance flag alone.

Dimensions are built to ASME B18.6.3-2013 and the thread form to ASME B18.6.4. Material is AISI 1016 to 1024 steel. Note that on the JDSP series the #9 diameter dimensions fall outside ASME B18.6.4; the #10 x 2 in. is within the standard.

For sheet metal alone it is longer than needed. The 2 in. shank on the JDSP185 is meant for anchoring through a thicker member, a spacer, or wood blocking into the substrate behind it. If you are only joining two layers of sheet, a shorter #10 leaves less point sticking out the back. Metallics runs other lengths in the JDSP series on request.

Order Metallics JDSP185, from the JDSP Type A tapping screw series, in #10 x 2 in. with a 5/16 hex washer head and Phillips drive, steel with zinc finish.