Metallics JSRM30 1/4-20 x 1/2 in. Round Head Slotted Machine Screws - 18-8 Stainless - Each

The JSRM30 ships as a jar of 100, and 100 is the order minimum. So one unit on an order equals one jar of 100 screws, not a single screw. For MRO stockrooms that run through 1/4-20 hardware, that is a single bin-ready container per order line.

The JSRM30 is cut 1/4-20 (20 threads per inch), which is the common 1/4 inch machine thread used on strut, fixture hangers, and threaded box hardware. At 1/2 inch of length it only has enough reach for thin sheet metal or a tapped boss; if you are going through a stacked bracket or a clamp with any thickness behind it, you need a longer length in the same thread.

Tensile strength is listed at 80,000 psi minimum with a hardness of Rockwell B85 to B95. That is well below a Grade 5 or Grade 8 steel bolt, so these are fastening hardware for enclosures, covers, straps, and fixture brackets, not a structural bolt. Metallics also notes that tensile values on stainless screws are approximations, since there is no single performance standard for stainless machine screws.

No. The JSRM30 is not Buy American compliant and is not ARRA compliant, with country of origin listed as multiple. On federally funded or domestic-preference work you will need a documented domestic-source fastener instead.

18-8 stainless is the austenitic 300-series grade used where plated steel would rust, so these hold up in wet locations, outdoor fixture mounting, and washdown areas far better than zinc-plated screws. In chloride-heavy environments (coastal, pool chemical rooms) 316 stainless is the step up. Note also that 18-8 is non-magnetic in the annealed state, which matters if you are working near sensors.

Machine screws like the JSRM30 have a blunt, non-tapered 1/4-20 machine thread, so they require a pre-tapped hole or a nut. They will not cut their own thread in sheet metal the way a self-drilling or sheet metal screw does. Pair them with a 1/4-20 nut, a tapped strut channel, or a device with a factory-tapped boss.

Metallics lists the field application as the electrical, plumbing, heating and air conditioning industries. In practice that means panel and enclosure covers, fixture and strap mounting, duct accessories, and bracket work where a corrosion-resistant 1/4-20 is wanted. The SRM series is the round head machine screw line within Metallics' fastener range.

A jar comes in at 1.01 lbs with the container measuring 3 x 3 x 2.15 in. Light enough to drop several into a van stock drawer, and the jar footprint fits a standard small-parts bin.