B-Line B281MSQHDG Eaton series strut fittings and accessories, 3.5" Height, 6" Length, 6" Width, 4.70lbs, Steel, Square post base, centered, Post base for B22-2PL, Hot-dipped galvanized

The B281MSQHDG is a square post base made for B22-2PL strut, which is the back-to-back double channel post. It is a centered base, so the strut sits in the middle of the 6 x 6 inch plate rather than offset to one edge. If you are standing up single-channel strut instead, this is the wrong base for it.

It is steel with a hot-dipped galvanized finish, which is the finish B-Line specifies for exterior, rooftop and damp locations. Hot dip coats cut edges and weld seams as well as flat surfaces, so it holds up better than pre-galvanized or plain finish where it will see weather. For salt spray or chemical exposure, stainless is the better call.

Plate footprint is 6 inches by 6 inches, with an overall height of 3.5 inches. Lay out your concrete pad or steel surface for a full 6 inch square so the anchor pattern is fully supported at the corners. Total weight of the fitting is 4.7 lb.

No. The B281MSQHDG is the post base fitting only, 4.7 lb of galvanized steel. Concrete anchors or through-bolts for the floor, and the channel nuts or bolts that tie the B22-2PL strut into the base, are ordered separately and sized to your substrate.

Centered, like the B281MSQHDG, is what you want for a freestanding post carrying load straight down, such as rooftop pipe stands or equipment frames, because the load lands over the middle of the 6 x 6 inch plate. An offset or edge base is for setting a post tight against a wall or curb where a centered plate would not clear. Pick based on where the post has to land, not on the load.

Yes, B281MSQHDG is the Eaton B-Line manufacturer part number. The HDG suffix identifies the hot-dipped galvanized version, so if a drawing calls out a plain or pre-galvanized square post base you are looking at a different finish code.