Metallics JMHTB38 Bolts M3 x 8 C8.8 Hx Tap Blt St-zn (Jar 100)

It's an M3 metric bolt with an 8mm length and a 0.5mm thread pitch, right hand thread. M3 x 0.5 is the standard coarse metric pitch for a 3mm bolt, so it mates with standard M3 nuts and M3 tapped holes. Thread runs the full length of the shank to the underside of the head, which is what makes it a tap bolt rather than a partially threaded hex cap screw.

That's the stated application for these Metallics hex tap bolts, mounting motors to machinery, and they're also common in automotive and truck repair. The bolt is Grade 8.8 medium carbon steel, heat treated to Rockwell C22-32, with a yield strength of 92,800 psi minimum. At M3 the individual bolt is small, so it suits small motor frames, covers, and clamp hardware rather than heavy structural anchoring.

No. The JMHTB38 is not Buy American compliant and is not ARRA compliant; country of origin is listed as multiple. If your project carries domestic sourcing requirements, this bolt won't satisfy them.

The JMHTB38 ships as a jar of 100 bolts, and the jar is the order minimum, so 100 pieces is the smallest quantity. Jar packaging is the reason for the JMHTB prefix; the MHTB side of the series is the same bolt in other pack configurations.

The JMHTB38 is carbon steel with a zinc finish. Zinc plating handles indoor and sheltered damp conditions, which covers the electrical, plumbing, heating and air conditioning work it's listed for. For direct weather exposure, wash-down, or coastal installs, go to stainless rather than zinc plated steel.

Not necessarily. These hex tap bolts are made with a washer face beneath the head, which gives a finished bearing surface against the part. Add a flat washer only if you're clamping soft material, oversized holes, or slotted mounting feet where you need to spread the load.

Grade 8.8 is the heat treated medium carbon metric class, roughly the metric counterpart to SAE Grade 5, and on the JMHTB38 it's confirmed by a Rockwell C22-32 hardness. A low-grade unhardened bolt of the same M3 x 0.5 thread will fit the hole but won't carry the same clamp load, so don't swap one in where an 8.8 was specified by the equipment maker.

The JMHTB38 is fixed at M3 x 8mm, but other sizes and quantities in the Metallics MHTB and JMHTB hex tap bolt line are available by request. If you need more thread engagement than 8mm gives you, ask for a longer length in the same series rather than stacking washers.

The packaged jar weighs 159 g. It's a small container, listed at 3 in long and 2.15 in high, so it stocks easily on a van shelf or in a parts bin drawer.