Metallics JFM35 5/16-18 x 1/2 in. Flat Head Slotted Machine Screws - Steel Zinc - Each

Yes. The JFM35 is a 5/16-18 UNC machine screw, 18 threads per inch, cut to the ANSI/ASME B1.1 thread standard. That means it mates with any standard 5/16-18 coarse tapped hole, nut, or strut channel nut. It will not work in a 5/16-24 fine thread hole.

The flat head on the JFM35 runs 0.165 to 0.191 in. in height with a head width of 0.556 to 0.597 in., so your 82 degree countersink has to be at least that wide at the surface and that deep for the head to sit flush. Head dimensions follow ASME B18.6.3-1998, so it drops into any prep machined to that standard.

The JFM35 carries a 3150 lb minimum tensile strength with a hardness of Rockwell B70 to B100, made from AISI 1006 to 1022 low carbon steel. That is adequate for electrical enclosures, panel and device mounting, and general MRO work. It is not a graded structural bolt, so do not substitute it where a drawing calls for a Grade 5 or Grade 8 fastener.

No. The JFM35 is not Buy American compliant and is not ARRA compliant, with country of origin listed as multiple. If your contract carries a domestic sourcing clause, this part will not satisfy it.

At 1/2 in. overall length with a flat head, the full 1/2 in. is measured from the top of the head down, since flat heads are measured overall. Subtract the head height (0.165 to 0.191 in.) and you have roughly 5/16 in. of thread below the countersunk surface. That is short, so it suits thin sheet metal, enclosure covers, and device plates rather than thick stacked material.

The JFM35 is zinc plated carbon steel, which is a mild corrosion barrier intended for dry indoor use. In wet, washdown, coastal, or chemical environments the plating sacrifices and the steel underneath rusts. For those openings go to a stainless machine screw in the same 5/16-18 x 1/2 in. size instead.

They ship in a jar of 100 pieces, and 100 is the order minimum. The jar weighs 1.286 lbs. Good if you want a shop-stock container for the van or a parts bin rather than a loose handful.

Slotted drive, with a slot 0.072 to 0.084 in. wide and 0.058 to 0.088 in. deep. Use a flat blade tip that matches that width. Slotted heads cam out easily under a power driver, so hand driving or a low-torque clutch setting gives better results, especially when you are pulling a flat head down flush.