Metallics JRMB2 1/4-28 x 1/2 in. Round Head Slotted Machine Screws - Brass - Each

The JRMB2 is 1/4-28, which is the fine thread pitch at 28 threads per inch. It will not thread into a 1/4-20 tapped hole. If the box, strap, or fixture you are fastening into is tapped 1/4-20 (the coarse pitch), you need a 1/4-20 screw instead. Threads are cut to ANSI/ASME B1.1.

Head height is 0.16 to 0.175 inch and head diameter is 0.443 to 0.472 inch, built to ASME B18.6.3. That matters on two counts: the domed head sits proud of the surface rather than flush, so it will not work in a countersunk hole, and at under half an inch across it needs a clearance hole small enough that the head has bearing all the way around.

Brass is what the JRMB2 is made from, and it is the usual choice where you want a non-magnetic, corrosion-resistant fastener, or where you are matching brass hardware and terminals so you are not mixing dissimilar metals at a connection point. Steel is stronger, so for structural or high-torque fastening a steel or stainless screw is the better call.

They ship 100 to a jar, and 100 is the minimum order count. You are buying a counted jar, not loose pieces.

No. The JRMB2 has a round, domed head that bears on the surface of the material. A countersunk hole is cut for an 82 degree flat head and a round head will not seat in it, leaving the screw sitting high and loose. Order a flat head brass machine screw in 1/4-28 for that hole.

The JRMB2 carries a compliant flag for both Buy American and ARRA. Point of origin on the part is China. On a federally funded job where the specifying authority treats country of origin as the governing test, get that reconciled with your spec writer before you submit it.

Yes, the JRMB series runs beyond this one size. Other sizes and quantities are available by request, so if you need 1/4-28 in a longer length or a different diameter in the same brass round head slotted configuration, ask rather than substituting a steel screw into a brass assembly.