Metallics JMSBHC1220 Bolts M12 x 20 HXBT SS (Jar 50)

It is a DIN 933 hex head bolt, which is the fully threaded metric hex bolt standard, in M12 x 20 mm. At a 20 mm length there is effectively no unthreaded shank, so use it for clamping thin assemblies, strut, channel, and equipment feet rather than anywhere you need a shoulder bearing in a hole.

Thread pitch is 1.75 mm, which is the coarse M12 x 1.75 thread. Any standard coarse M12 nut, coupling, or tapped hole will take it. The threads are made to ISO 724 and ISO 965-1, so fit with other metric coarse hardware is to spec. If your tapped hole is M12 x 1.5 fine thread, these will not thread in.

They are 18-8 stainless, classed A-2 under ISO 3506. That is the austenitic 300 series grade used for general outdoor and damp indoor work, so rooftop equipment, exterior strut, and wet mechanical rooms are all within its range. A-2 is not the choice for coastal salt spray or chlorinated pool environments, where 316 (A-4) stainless is the usual step up.

They ship 50 to a jar, and 50 count is the order minimum, so the jar is the smallest buy. The filled jar weighs 1624 g. Metallics does make other sizes and quantities available by request if 50 of this size is not what the job needs.

The head is a plain hex, and DIN 933 sets the maximum width across flats for the diameters in this group at 17, 19, and 22 mm. For M12 under DIN 933 that puts you on a 19 mm socket or wrench. There is no flange and no washer face feature to work around, so a standard six point socket seats fine.

Bolts only. The jar of 50 is M12 x 20 hex head bolts with nothing else packed in, so order matching A-2 or 18-8 stainless M12 coarse nuts and flat washers separately. Keeping the nut and washer in the same stainless family avoids galvanic issues and thread galling with a plated nut.