Metallics JMHTB312 Bolts M3 x 12 C8.8 Hx Tap Blt St-zn (Jar 100)

It's an M3 metric bolt, 12mm long, with a 0.5mm thread pitch and right-hand threads. That 0.5 pitch is the standard coarse pitch for M3, so it mates with any standard M3 coarse tapped hole or nut. Because it's a tap bolt, the thread runs the full length of the shank right up under the head, so there is no unthreaded grip section to worry about with thin brackets or shallow tapped holes.

Yes, that's the intended use. The JMHTB312 is property class 8.8, a medium carbon steel bolt that has been heat treated, with a hardness of Rockwell C22-32. Class 8.8 is the common medium-strength metric grade for machinery and equipment mounting, and the description calls out motor mounting plus automotive and truck repair as typical applications. At M3 x 12 it's a small-diameter fastener, so it suits small motor frames, control components, and bracketry rather than heavy structural loads.

Metallics lists the JMHTB312 as both ARRA compliant and Buy American compliant, which is what institutional and government procurement typically needs documented on federally funded work. Country of origin is listed as multiple, so if your specification requires a single named origin on the submittal, that is worth confirming for the lot you receive.

No. The JMHTB312 is a metric M3 bolt with a 0.5mm pitch, so it will not thread into an imperial tapped hole such as a #4-40 or #6-32. Metric and inch threads are not interchangeable even where diameters look close. If the equipment is domestic machinery with inch threads, order an inch-series hex bolt instead; if it's imported motors or equipment, metric is almost always correct.

The finish is zinc plating over steel, which handles indoor and normally dry service, including mechanical rooms, panel work, and equipment mounting. Zinc plating is a sacrificial coating, not stainless, so in constant wet, washdown, coastal, or chemical exposure it will eventually corrode. For those conditions choose a stainless hex bolt instead.

The JMHTB312 ships as a jar of 100 bolts, and the jar is the minimum order unit, 100 count. The jar packaging keeps small M3 hardware together on a service truck or in a parts bin rather than loose in a bag. Other sizes and quantities can be requested.

A tap bolt is threaded all the way to the underside of the head, while a standard hex cap screw leaves part of the shank unthreaded. Full threading, as on the M3 x 12 JMHTB312, means you get maximum thread engagement in a shallow tapped hole and you can clamp thin sheet or stacked brackets without the unthreaded shank bottoming out. The trade-off is that a partially threaded bolt gives a better shear bearing surface when the joint is loaded across the shank. The JMHTB312 also carries a washer face under the hex head, which gives a clean bearing surface against the part.

Metallics lists the field application as the electrical, plumbing, heating, and air conditioning industries, so the same jar serves a mechanical contractor mounting small blowers, control boards, or valve actuators as well as an electrician fastening devices inside enclosures. It's a general-purpose metric machinery fastener, not an electrical-only item.

Metallics lists the product weight at 113 g for the jar. That makes it easy to add to an order or keep several sizes stocked on a van without any meaningful weight penalty.