Metallics JFM83SS 6-32 x 2 in. Flat Head Slotted Machine Screws - 18-8 Stainless - Each

Dimensions conform to ASME B18.6.3-1998, the inch-series standard for slotted and recessed head machine screws, with threads to ANSI/ASME B1.1 and material called out to SAE. That combination is what lets you show head and thread conformance on a submittal. Note it is not Buy American compliant and not ARRA compliant, with multiple countries of origin, so it will not clear a domestic-content requirement on a federally funded job.

Flat head means a countersunk head, so it finishes flush in a chamfered or countersunk hole. The head measures 0.238 to 0.262 in. across with a head height of 0.069 to 0.083 in., so the hole needs an 82 degree countersink roughly a quarter inch wide to bury it. In a plain drilled hole with no countersink the head will stand slightly proud. If you need the head to bear on a flat unprepared surface, a pan or round head 6-32 is the better pick.

18-8 stainless is specified for general atmospheric corrosion resistance, which covers damp and outdoor-exposed locations, food processing machinery and refrigeration equipment. It also holds its strength better than plain steel as operating temperature climbs. For continuous salt spray or chemical exposure, a 316 grade fastener is the heavier-duty answer; for ordinary damp mechanical rooms, kitchens and refrigeration gear, 18-8 is the normal call.

The JFM83SS is rated to a 550 lb minimum tensile strength with a hardness of Rockwell B85-B95. Worth knowing for anyone writing a spec: Metallics states hardness and tensile figures for stainless machine screws as guides only, because there is no national performance standard for stainless machine screws. If your drawing calls out a graded fastener with certified mechanical properties, a 6-32 stainless machine screw is not the part that satisfies it.

A machine screw like the JFM83SS has a uniform 6-32 UNC machine thread with a blunt end. It needs a tapped hole or a nut, and it will not form its own thread in sheet metal or cut into wood. Use it where there is existing 6-32 tapped prep, a 6-32 nut, or a threaded insert. If the hole is unthreaded sheet metal, you want a self-tapping sheet metal screw instead.

They ship in a jar of 100, and 100 is the order minimum, so one jar is the smallest buy. Jar weight is 0.69 lbs. For a service van or an MRO crib that goes through long 6-32 screws on device and fixture work, a single jar is a sensible shelf quantity. Other sizes and quantities in the FM and FMP series are available by request.

Metallics lists the field application as the electrical, plumbing, heating and air conditioning industries. In practice the 2 inch length shows up where a device or plate has to be fastened through depth: devices set behind thick finish material, extension rings, HVAC control and panel covers, refrigeration enclosures, and food-service equipment where the stainless matters more than the strength does.