Metallics JSRM131 3/8-16 x 1-1/4 in. Round Head Slotted Machine Screws - 18-8 Stainless - Each

The JSRM131 is a 3/8-16 machine screw, 1-1/4 inches long, with 16 threads per inch on a coarse 3/8 inch diameter. That means it mates with any standard 3/8-16 tapped hole or nut, which is what you'll find on most strut channel fittings, junction box mounting lugs and equipment feet in commercial electrical work.

They're 18-8 stainless, the common austenitic grade used where corrosion is the concern rather than high strength. That makes the JSRM131 a reasonable pick for damp locations, exterior boxes, coastal-adjacent sites and wash-down areas where a plated carbon steel screw would rust. Hardness runs Rockwell B85 to B95.

Tensile strength on the JSRM131 is 80,000 psi minimum. Worth knowing that stainless tensile numbers are approximations, since there is no single performance standard for stainless machine screws. If your drawing calls out a graded fastener (Grade 5 or Grade 8 carbon steel), a stainless screw is not a substitute for it.

Head width runs 0.67 to 0.708 inch and head height 0.237 to 0.256 inch. If you're fastening through a slotted bracket or a strut channel, the head needs a bearing surface narrower than about 0.67 inch to span the slot without falling through, and you need roughly a quarter inch of clearance above the surface for the crown.

They come in a jar, with an order minimum of 100 count. So the smallest buy is a 100-piece jar rather than a loose handful, which suits an MRO crib or a truck stock bin. The packed jar weighs 4.73 pounds.

The JSRM131 is flagged compliant for both ARRA and Buy American in the manufacturer's data, with country of origin listed as China. On a federally funded project, confirm which clause your contract actually invokes, since the flag and the origin need to be reconciled against the specific FAR provision on your job.

Mechanically yes, any 3/8-16 tapped hole takes them. Just be aware that 18-8 stainless in direct contact with galvanized or plain steel in a wet location sets up galvanic action, and the zinc or steel is the one that corrodes. Dry interior runs are not a concern; exterior and wash-down locations are where you'd want an isolating washer or a matched-material fastener.