B-Line Eaton series strut channel, 1" channel height, 120" channel length, 1.62" channel width, Steel, 12 Gauge, SH hole pattern, B42 channel type, Ho

The B42SH strut is hot-dipped galvanized steel, which is the finish specified for exterior runs, rooftop equipment supports, parking structures, and damp or wash-down interiors. Plain painted or pre-galvanized strut is the indoor-only option; hot-dip is the one you want where weather or moisture reaches the steel.

SH is the slotted-hole back pattern, so the B42SH-120HDG stick comes punched along the back rather than solid. That lets you through-bolt the channel to studs, joists, or concrete anywhere along the run without drilling on site, and it drops the weight of the stick. If you need an unpunched back for a continuous seal or full section strength, order a solid-back B42 instead.

It is 12 gauge steel, the standard structural thickness for strut channel, and a full 120 inch stick weighs 13.6 lb. That weight matters for two things: a single installer can carry and set a stick overhead, and you can figure hanger and anchor loading knowing the dead weight of the channel itself before conduit or pipe goes on it.

B42 at 1 inch deep is the half-height profile. Use it for lighter runs, single conduit hangers, trapeze spans that are short, and anywhere headroom is the constraint. When you are spanning further between supports or carrying heavier pipe, cable tray, or mechanical equipment, step up to a full 1-5/8 inch deep channel, which has more section depth to resist deflection. Both share the same 1.62 inch face, so the fittings and strut nuts carry over between them.

It ships as a full 120 inch stick, part number B42SH-120HDG. Strut is field cut with a bandsaw or chop saw. If you cut it, touch the exposed edge with a cold galvanizing compound, otherwise the raw steel at the cut is the first place rust starts on an exterior hot-dipped run.