Metallics JSPMP116SS 1/4-20 x 2-1/2 in. Pan Head Phillips Machine Screws - 18-8 Stainless - Each

It's a 1/4-20 machine screw, 2-1/2 inches long, with 20 threads per inch. That's the standard UNC coarse pitch for 1/4 inch, so it mates with any 1/4-20 tapped hole or nut, including the tapped holes in most steel electrical boxes and strut fittings.

These ship in a jar with a minimum order of 100 count. You're buying a 100-piece jar, not an individual screw, so plan the count against the job before you order.

No. A machine screw has a uniform straight thread with no point, so it needs a pre-tapped hole, a nut, or a threaded insert. The 1/4-20 thread will not form its own thread in wood, drywall, or sheet metal. For those materials you want a self-tapping sheet metal screw or a wood screw instead.

A #3 Phillips bit. The recess diameter is 0.274 inch with a gaging depth of 0.118 to 0.144 inch, so a #2 bit will sit shallow in the recess and cam out when you torque it down. Load a #3 in the impact or screwgun before you start a run.

Head height runs 0.162 to 0.175 inch and head width 0.473 to 0.492 inch, dimensioned to ASME B18.6.3-2010. A pan head is a rounded low-profile head with a flat bearing surface, so it sits on top of the material rather than countersinking. If you need the head flush with the surface, a flat head screw in a chamfered hole is the right choice instead.

18-8 stainless is an austenitic chrome-nickel stainless and it's the usual pick for damp, wet, and exterior work where a plain or zinc plated steel screw would rust. It's non-magnetic in the annealed condition and holds up in general weather exposure. For constant salt spray or coastal marine service, 316 stainless is the step up.

80,000 psi minimum, to SAE material standard. Treat that as an approximation: there is no single standard governing performance requirements for stainless machine screws, so if your drawing calls out a specific bolt grade with a verified proof load, a graded carbon steel fastener is what that spec wants.

Metallics lists the JSPMP116SS as both ARRA compliant and Buy American compliant, with country of origin China. If your contract language requires domestic melt and manufacture rather than the compliance designation, verify against your specific contract clause before submitting.

Metallics offers other sizes and quantities in the SPMP pan head Phillips line by request. The JSPMP116SS specifically is the 1/4-20 x 2-1/2 inch, 18-8 stainless, 100-count jar.

The packaged jar is listed at 3.2 lbs, with package dimensions of 5.75 by 3.5 by 3.5 inches. Useful if you're consolidating a fastener order onto a pallet or figuring van load for a service truck.