Metallics JSTS15 8 x 1 in. Pan Head Slotted Tapping Screws - 18-8 Stainless - Each

The JSTS15 #8 x 1 inch pan head tapping screws ship in a jar, with a minimum order of 100 pieces. That jar is the sales unit, so plan quantities in multiples of 100 rather than piece counts.

The JSTS15 is a Type A tapping screw with a gimlet point, so it forms its own thread as it drives into sheet metal or similar material. The gimlet point helps it start, but Type A screws are still intended to go into a prepared hole sized for the fastener, not to drill their own through steel. Thread pitch is 15 threads per inch.

It can happen. Driving 18-8 stainless fasteners into aluminum or steel creates a galvanic couple, and in wet or salty environments that drives corrosion of the softer base metal. For exterior or damp locations, isolate the joint or match the fastener material to the base metal. In dry indoor work the 18-8 stainless body is the reason to choose it, since the screw itself resists rust.

No, a pan head is not a flush fastener. The head measures 0.306 to 0.322 in. across and stands 0.085 to 0.096 in. above the surface, so it sits proud and gives a broad bearing face on sheet metal or thin panels. If you need the head buried, use a flat or oval head in a countersunk hole instead.

No. The JSTS15 screws are not Buy American compliant and are not ARRA compliant, with country of origin listed as multiple. For federally funded work with domestic sourcing requirements, you will need a domestically produced fastener.

Slotted drive is cam-out prone under a drill or impact, so these are better suited to hand driving or a low-speed driver with a matched blade. Slot width runs 0.045 to 0.054 in. and slot depth 0.045 to 0.058 in., so use a flat blade that fills the slot. If you want a driver that holds itself, pick a Phillips version instead.

Minimum torsional strength is 39 lb-in. That is the driving limit, and stainless is softer than hardened carbon steel, so back off the clutch on a driver and finish by hand. Overdriving a Type A screw also strips the thread it just formed in thin material.

Head and slot dimensions follow ASME B18.6.3-2013, and the thread form follows ASME B18.6.4. Note that dimensions for a #9 diameter fall outside ASME B18.6.4.

Metallics lists the JSTS series for electrical, plumbing, heating and air conditioning work. Typical use is fastening straps, plates, brackets and thin sheet metal where a broad pan head bears on the part and the stainless body resists rust in damp mechanical rooms.

The JSTS15 itself is the #8 diameter, 1 in. length version in the JSTS series. Metallics notes other sizes and quantities in the series are available by request, so if you need a shorter or longer pan head slotted tapping screw in 18-8 stainless, ask for the matching JSTS number.

A jar comes in at 0.54 lbs, with the container measuring 3 in. by 3 in. by 2.15 in. Light enough that shipping several jars on one order is trivial.