Metallics HTB1B Bolts 1/4-20 x 3/4 Hx Tap Blt St-zn (Box 2500)

It's a 1/4-20 hex tap bolt, so 1/4 inch diameter with 20 threads per inch, UNC coarse. It threads into any 1/4-20 tapped hole, strut nut, or standard 1/4-20 hex nut. Threading runs the full length on a tap bolt, which is what separates it from a partially threaded hex cap screw.

The HTB1B is zinc plated steel. That's fine for dry indoor runs and protected locations, and it handles incidental moisture, but zinc plating is a sacrificial coating that will eventually rust in direct weather, wet locations, or corrosive air. For exposed exterior strut, rooftop, or washdown areas, specify the 18-8 stainless version of the hex tap bolt instead of the steel-zinc.

The HTB1B ships as a box of 2,500 pieces, and 2,500 is the order minimum, so it's a bulk buy rather than a small pack. Full box weight is 23.98 lbs. Other sizes and quantities are available by request.

A tap bolt like the HTB1B is threaded the entire length of the shank. A hex cap screw has a plain unthreaded shoulder under the head. Full threading is what you want when you're threading into a tapped hole, a strut channel nut, or clamping two thin sheet metal parts where a grip length would bottom out before the joint tightens. If the joint needs a smooth shank bearing in a reamed hole, use a cap screw instead.

Threads are made to IFI-199 (2014). That is the standard inch thread spec, so the bolts interchange with any off the shelf 1/4-20 nut, strut nut, or tapped hole from another manufacturer.

Country of origin on the HTB1B steel-zinc hex tap bolt is China. That is the value to put on a submittal or material disclosure sheet for the part as supplied.