Metallics G8HC754 Bolts 3/4-10 X 4 G8 Hxbt St-Yzn (Box 20)

The G8HC754 is Grade 8, rated 150,000 psi minimum tensile and 130,000 psi minimum yield, with a hardness of Rockwell C33-39. Grade 5 in this diameter tops out well below that, which is why Grade 8 is specified in automotive and fleet work where the joint needs more clamp load than a Grade 5 can carry. The tradeoff is that the heat-treated medium carbon steel is less forgiving of shock and notching than a lower grade, so don't reuse stretched bolts and torque to the Grade 8 value, not the Grade 5 value.

Not as a domestic-content item. The G8HC754 is flagged Buy American non-compliant and ARRA non-compliant, with country of origin listed as multiple. If your contract carries Buy American or ARRA domestic sourcing requirements, you need a domestically manufactured Grade 8 fastener instead.

Across-flats head width is 1.100 to 1.125 inch, which is a 1-1/8 inch wrench or socket. Across corners the head measures 1.240 to 1.299 inch, so plan clearance around the head accordingly in tight bracket pockets.

Finish is yellow zinc plating over steel. That gives decent protection in dry or sheltered conditions and in vehicle chassis service, but zinc plating is a sacrificial coating, not stainless. For continuous wet exposure, direct ground contact, or coastal installs, expect the plating to be consumed over time and specify a hot-dip galvanized or stainless fastener instead. Note also that plated Grade 8 should not be galvanized after the fact, and mixing it with galvanized nuts can cause thread fit problems.

These ship 20 to a box, and 20 each is the order minimum, so it's a full-box purchase rather than a single piece. If you need a different size or a different quantity, other sizes and quantities in the G8HC and JG8HC series are available by request.

No. The G8HC754 is sold as bolts only, 20 hex cap screws to the box. You'll need to source 3/4-10 nuts and any hardened washers separately, and for a Grade 8 joint those should be matching-grade hardware so the nut and washer don't become the weak point.

Medium carbon steel in the AISI 1021 to 1045 range, quenched and tempered to Rockwell C33-39. That heat treatment is what gets it to Grade 8 strength. Practical consequence: don't weld it, don't flame-cut it, and don't re-heat the bolt, because any of those will draw the temper and drop it below Grade 8 properties.