Metallics JFWP41 12 x 1-1/2 in. Flat Head Phillips Wood Screws - Steel Zinc - Each

The JFWP41 is steel with a zinc finish, which is a plating for dry interior and protected service, not a corrosion coating for weather exposure or treated lumber. For exterior strut mounting, wet locations, or contact with ACQ pressure-treated wood, specify a stainless steel or hot-dip galvanized wood screw instead. Indoors on blocking, backboards, plywood, and wood studs, zinc plated steel is the normal choice.

They are built to ASME B18.6.1, with threads to ASME B18.6.1-1997, at 11 threads per inch for the #12 diameter. That is the standard a spec writer or inspector will be looking for on a wood screw submittal. Note that the JFWP41 is not Buy American compliant and is not ARRA compliant, with country of origin listed as multiple, so it will not clear a federally funded job carrying domestic sourcing requirements.

They ship in a jar of 100, and 100 is the order minimum, so a jar is the smallest unit. Jar weight is listed at 1.3 lbs. If you need a different size or a different count, Metallics makes other lengths and diameters in the JFWP flat head Phillips wood screw series.

That is exactly the intended use. Metallics lists the JFWP41 for the electrical, plumbing, heating and air conditioning trades, and a #12 x 1-1/2 in. flat head Phillips is the common fastener for anchoring device boxes, straps, clamps, panel backboards, and equipment brackets to wood studs and blocking. The flat head seats flush so a box or strap flange sits tight against the mounting surface.

Partly threaded. Metallics states the thread runs two thirds of the length on screws over an inch, so on the 1-1/2 inch JFWP41 you get roughly an inch of thread with an unthreaded shank under the head. That shank is what lets the screw clamp two pieces of wood together instead of jacking them apart, so pre-drill the top member at shank diameter when you want a tight pull-down.