Metallics G8HC75112 Bolts 3/4-10 X 1-1/2 G8 Hxbt St-Yzn (Box 50)

Yes. The G8HC75112 is a 3/4 inch diameter hex cap screw with 10 threads per inch, which is the standard UNC coarse pitch for 3/4 inch. Any 3/4-10 nut threads onto it. Measured shank diameter runs 0.7410 to 0.7500 inch. For full Grade 8 joint strength, pair it with a Grade 8 (or Class 8) nut rather than a Grade 2 or 5 nut.

Strength. The G8HC series is Grade 8, rated 150,000 psi minimum tensile and 130,000 psi minimum yield, with a Rockwell C33-39 hardness from the medium carbon steel being heat treated. Grade 5 of the same diameter cannot reach those numbers, which is why these are used in automotive and fleet work where the joint has to carry more load. If your drawing calls out Grade 5 only, a Grade 8 substitution is harder and less ductile, so don't swap it without the engineer's say.

No. The G8HC75112 is not Buy American compliant and is not ARRA compliant, with country of origin listed as multiple. On a federally funded project with domestic sourcing requirements, you'll need a domestically manufactured Grade 8 cap screw instead.

Across-flats width on the hex head measures 1.100 to 1.125 inch, so a 1-1/8 inch socket or wrench is the size to bring. Head type is a standard hex, not a flange or socket head.

The G8HC75112 is steel with a yellow zinc plated finish, which gives moderate corrosion protection for covered or intermittently damp service. It is not stainless and it is not hot dip galvanized, so for direct weather exposure, coastal air, or submerged conditions you want a hot dip galvanized or stainless fastener instead. Keep in mind stainless will not match the 150,000 psi tensile of Grade 8.

These ship as a box of 50, and 50 each is the order minimum, so partial counts aren't broken out. Other sizes and quantities in the G8HC series are available by request if 1-1/2 inch under head isn't the length you need.

Length is measured under the head, so a 1-1/2 inch bolt gives you 1-1/2 inch of total shank to work with. After the nut and any washers, usable grip is less than that, and 3/4-10 coarse thread needs enough protruding thread to fully engage the nut (roughly one diameter of engagement for full strength). For stacked steel much over about an inch, step up to a longer length in the G8HC series.

Medium carbon steel in the AISI 1021 to 1045 range, quench and temper heat treated to reach Grade 8 properties. That heat treatment is what gives the Rockwell C33-39 hardness, and it is also why you should never weld on or re-heat a Grade 8 bolt, which destroys the temper.