Metallics JG5HCF86 Bolts 7/16-20 X 3 G5 Hxbt St-zn (Jar 50)

Fine thread. The JG5HCF86 is a 7/16-20 hex bolt, 20 threads per inch, which is the UNF fine pitch for 7/16 diameter. Coarse 7/16 is 14 threads per inch, so it will not thread into a 7/16-14 tapped hole or take a coarse nut. Threads are made to ASME B18.2.1-2012.

It is a medium carbon steel cap screw, heat treated to Grade 5 with 105,000 psi minimum tensile and yield and a hardness of Rockwell C19-30. That is the normal strength class used to bolt motors to machinery and for automotive and truck repair work, which is exactly what this bolt is built for. If your drawing calls for Grade 8 or a metric class 10.9, step up instead of substituting this one.

The hex head measures 0.612 to 0.625 inch across the flats, so a 5/8 inch wrench or socket is the right size. Wrenching height on the head is 0.195 inch, so use a six point socket if the head is in a tight or recessed pocket.

The finish is zinc, specifically a zinc chromate plating over the steel. That handles indoor industrial use, equipment rooms and shop work well. For sustained outdoor exposure, washdown areas or coastal sites, go hot dip galvanized or stainless instead, since plated zinc is a thin sacrificial coat.

The JG5HCF86 is flagged compliant for both Buy American and ARRA. Country of origin is listed as multiple, so if your contract requires a specific domestic origin certificate on the lot you receive, ask for documentation against the shipped lot.

Both belong to the same Grade 5 hex cap screw family, the G5HC and JG5HC series. The J prefix is the jar pack, which is what JG5HCF86 is: 7/16-20 x 3 zinc plated Grade 5, 50 to the jar. The spec of the bolt itself does not change with the pack.

Head height on the 7/16-20 Grade 5 hex bolt runs 0.272 to 0.291 inch, so figure a little over a quarter inch of projection above whatever you are clamping. Worth checking when a guard, belt, or sheet metal cover passes close to the bolt head.