Metallics JFWP27 10 x 1/2 in. Flat Head Phillips Wood Screws - Steel Zinc - Each

Use a #3 Phillips bit. The recess on these #10 screws measures 0.245 to 0.258 inch in diameter with a 0.123 to 0.146 inch depth, which is why a #2 bit will cam out on them. Stock #3 bits on the truck if you are driving these in volume.

Yes, if the hole is countersunk. The JFWP27 is a flat head screw with a head 0.34 to 0.385 inch across and only 0.116 inch of head height, so it seats flush in a matching 82 degree countersink or in the countersunk holes already punched in device straps and mounting plates. On an un-countersunk flat surface the head will stand proud by that 0.116 inch.

Treat them as interior and dry-location fasteners. The JFWP27 is steel with a zinc finish, which handles normal indoor humidity but is not a stainless or hot-dip coating. For exterior walls, wet locations, or anywhere in contact with treated lumber, use a stainless or hot-dip galvanized wood screw instead of zinc plated steel.

No. The JFWP27 is not Buy American compliant and is not ARRA compliant, and its country of origin is listed as multiple. On federally funded or state work carrying domestic-sourcing language, source a domestically produced fastener instead.

In hardwood, yes. The JFWP27 has a tapered point and 13 threads per inch, which starts easily in softwood, plywood, and furring but can split oak, maple, or hardwood trim at #10 diameter. Drill a pilot sized to the root diameter and countersink for the flat head. In pine and sheathing it will drive without a pilot.

They come in a jar of 100, and 100 is the order minimum, so you buy a jar at a time rather than loose pieces. A jar runs about 0.4 lbs, which is convenient for a van stock bin or a shop shelf rather than a bulk pallet buy.

Yes. The JFWP27 is built to ASME B18.6.1, with threads to ASME B18.6.1-1997, so the head diameter, head height, thread pitch, and recess dimensions are to the published standard. That matters when a submittal or a facility spec calls out standard-dimension flat head wood screws rather than a proprietary fastener.

Metallics lists the JFWP series for the electrical, plumbing, and heating and air conditioning trades. In practice it is the short screw for fastening device boxes, straps, pipe clamps, hangers, and equipment plates to wood studs, blocking, or furring where a longer screw would blow through. Electricians and MRO crews keep a jar in the van for exactly that.

Yes. The JFWP line runs other diameters, lengths, and quantities beyond the #10 x 1/2 inch in model JFWP27, available by request. If you are standardizing a building or a shop bin on one head and drive, you can keep the flat head Phillips zinc configuration and change only the length.