Metallics JFWPB41 12 x 1-1/2 in. Flat Head Phillips Wood Screws - Brass - Each

The JFWPB41 ships in a jar of 100 screws, and 100 is the order minimum, so a jar is the smallest buy. Metallics does offer other sizes and quantities in the JFWPB brass wood screw line by request.

Use a #3 Phillips bit. The recess on the JFWPB41 runs 0.270 to 0.283 inch in diameter and 0.148 to 0.171 inch deep, which is why a #2 bit will cam out and chew up the head. Brass is soft, so a correctly sized bit and moderate torque matter more here than on steel screws.

The JFWPB41 is made to ASME B18.6.1, with threads to ASME B18.6.1-1997. That is the inch-series wood screw standard, so head, recess and thread dimensions are to spec rather than proprietary. Worth knowing for a government or institutional job: these are not Buy American compliant and not ARRA compliant, with multiple countries of origin.

Yes, that is what the flat head is for. The head measures 0.389 to 0.438 inch across with a 0.132 inch head height, so a standard 82 degree countersink for a #12 flat head screw will bring it flush or slightly below the surface. Drill the countersink to match the larger end of that head width range if you want it fully buried.

Two reasons drive it on the job: brass does not rust, so it holds up in damp locations and outdoor-adjacent work, and it is non-magnetic and non-sparking, which matters around electrical and instrument work. Metallics lists the JFWPB series for the electrical, plumbing, heating and air conditioning trades. The tradeoff is strength, brass is softer than steel, so pilot-drill hardwood and do not drive these with an impact driver.

On the JFWPB brass wood screws, screws over 1 inch long carry thread over roughly two thirds of the length, so a 1-1/2 inch screw gives you about an inch of thread with a plain shank under the head. Thread pitch is 11 threads per inch. Practically, that means your pilot hole in the top piece can be clearance-drilled for the shank to pull the joint tight.

A #12 shank with 11 threads per inch and an inch of thread engagement is a heavier screw than the #6 and #8 sizes usually packed with boxes and straps, so it bites well into framing. Metallics lists the JFWPB series for electrical, plumbing and HVAC work. Keep in mind the material is brass, not steel, so for heavy hanging loads or anywhere torque is high, a steel screw is the stronger choice and brass is the one you pick for corrosion resistance or non-magnetic requirements.