Metallics JMHTB58 Bolts M5 x 8 C8.8 Hx Tap Blt St-zn (Jar 100)

Yes. The JMHTB58 is an M5 metric tap bolt with a 0.8 mm thread pitch, which is the standard coarse pitch for M5, and the thread is right hand. Shank length under the head is 8 mm, and as a tap bolt the thread runs all the way up to the washer face beneath the head, so there is no unthreaded grip length to work around in a shallow tapped hole.

Class 8.8 is medium carbon steel, heat treated, with a hardness of Rockwell C22-32. Metallics lists minimum yield strength of 92,800 psi for these bolts. That is the usual class for bolting motors to machinery frames and for automotive and truck repair work, which is exactly what Metallics calls out for the MHTB/JMHTB series. For structural steel connections, follow the engineer's stated bolt grade rather than substituting.

No. Metallics lists the JMHTB58 as not Buy American compliant and not ARRA compliant, with country of origin shown as multiple. On federally funded or domestic-preference work, you will need a domestically sourced fastener instead.

No. The JMHTB58 is a metric M5 with a 0.8 mm pitch, so it will not engage an inch-series tapped hole such as 10-24 or 1/4-20. Metric M5 is common on imported motors, pumps and enclosures; inch-threaded strut, channel and most North American boxes are not. Check the tapped hole or the existing fastener before ordering a jar.

The JMHTB58 is steel with a zinc finish. Zinc plating handles indoor and sheltered mechanical, plumbing, heating and air conditioning work, which is the application range Metallics lists for the series. For continuous wet exposure, coastal air, or direct ground contact, zinc plated carbon steel is the wrong choice and a stainless or hot dip galvanized fastener should be specified instead.

JMHTB58 ships as a jar of 100 bolts, and the jar is the minimum order quantity. It is a shop-bin package rather than bulk box, which suits a service truck or a maintenance crib. Metallics makes other sizes and quantities of the MHTB and JMHTB tap bolts available by request if you need a different length or a larger count.

A tap bolt is threaded the full length, right up to the washer face under the hex head, which is how the JMHTB58 is built. A standard hex cap screw leaves part of the shank unthreaded. Full thread is what you want when you are running into a tapped hole of unknown depth, through a thick casting, or when you need the shortest possible engagement, as on an 8 mm long M5 like this one. If your joint needs an unthreaded shoulder bearing in the clearance hole for shear, use a partially threaded hex bolt instead.

The jar of 100 is listed at 399 g. Light enough to carry several sizes on a van without thinking about it, which is part of why the jar pack is the standard MRO package for this series.