B-Line Eaton series strut channel, 1.62" channel height, 240" channel length, 1.62" channel width, Steel, 12 Gauge, S58 hole pattern, B22 channel type

Pre-galvanized steel is a mill-coated finish meant for indoor and protected, dry locations. It handles normal interior humidity fine, but for exterior runs, parking garages, coastal air or wash-down areas you want hot-dip galvanized or stainless strut instead. The zinc on pre-galv is thin and cut ends are left bare, so field cuts in a damp area will need cold galvanizing compound.

It is 12 gauge steel, which is the heavy-wall version of 1-5/8 strut rather than the lighter 14 or 16 gauge. That matters when the strut is spanning between hangers on a trapeze or carrying multiple conduit runs, since the gauge is what drives the allowable span and load. If your drawing calls out 12 gauge 1-5/8 channel, this is the section.

S58 is a slotted back pattern, so the channel is punched along its back rather than solid. Slots let you through-bolt hangers, all-thread and backing plates anywhere along the run instead of only at fitting locations, which is why it gets specified for pipe and conduit trapeze work. If you need a solid back for a continuous seal or full bearing surface, order the unpunched version instead.

The Eaton B-Line part number is B22S58-240GLV. That breaks down as B22 channel type, S58 slotted hole pattern, 240 inch length, GLV for the pre-galvanized finish. Quote that number and you get the 1-5/8 by 1-5/8, 12 gauge stick.

Yes, 12 gauge pre-galvanized steel channel cuts with a chop saw, bandsaw or portable band cutter, and a 240 inch stick is normally bought long and cut down on the job. Deburr the cut and hit the raw edge with cold galvanizing spray, since the pre-galv zinc does not cover the cut face.