Metallics JTSF44 6 x 2-1/2 in. Flat Head Phillips Tapping Screws - Steel Zinc - Each

It will, if the countersink is cut for a standard #6 flat head. The JTSF44 head measures 0.238 to 0.262 in. across and 0.069 to 0.083 in. high, so you need a countersink just over a quarter inch wide. In sheet metal too thin to countersink, the head will stand proud by roughly the head height, which is why flat heads get paired with dimpled or countersunk stock.

You need a pilot hole. The JTSF44 is a Type A tapping screw with a gimlet point, which means it's sharp enough to start and it cuts its own threads as it goes, but it is not a self-drilling screw with a drill tip. Punch or drill the hole first, then let the screw form the thread. Gaging diameter on the thread is 0.22 in., at 18 threads per inch.

A #2 Phillips bit. The JTSF44 uses a Phillips recess measuring 0.168 in. diameter, 0.094 in. deep, with a 0.029 in. recess width, which is standard #2 driver territory. Torsional strength is rated at 24 lb-in minimum, so back off the impact driver clutch if you're running these into heavier gauge material.

Zinc plating on carbon steel is a light corrosion coating, suitable for dry interior work like panel boxes, device mounting, and enclosure work. For sustained exterior exposure, wet locations, or coastal air, specify a stainless or hot dip galvanized fastener instead. The JTSF44 is steel with a zinc finish.

They ship in a jar, with a minimum order of 100 count. If your job calls for a different size or a different quantity, other configurations in the series are available by request.

Yes. The JTSF44 is built to ASME B18.6.4-1998 for dimensions, with threads to ASME B18.6.4. One caveat for anyone writing a submittal: within the JTSF line, dimensions for the #9 diameter are independent of ASME B18.6.4. The #6 size conforms.

Usually, yes. At 2-1/2 inches of length on a #6 shank, this one is meant for reaching through furring, backer, or stacked material into a thin metal substrate, not for fastening two pieces of sheet metal face to face. For box and device work you want a much shorter length in the same series. Order the length so the thread engages the substrate without running long past it.

Case hardness runs Rockwell C28-38, which is typical for a thread forming tapping screw and hard enough to cut threads in light gauge steel without the point rolling over. The steel is AISI 1016 to 1024. At 24 lb-in minimum torsional strength, the limit is usually how hard you drive it, not the material, so a clutch setting beats an impact gun on heavier stock.

Country of origin on the JTSF44 is listed as multiple, so it is not a fastener to write into a domestic-preference spec. If the job carries a Buy American or ARRA requirement, source a fastener with a single documented domestic origin.