B-Line B261-12ZN Eaton series strut fittings and accessories, 10.12" Height, 12" Length, 1.62" Width, 1.65lbs, Steel, Corner to brace length 10-1/8, Two hole knee brace, 45 deg, Load capacity 1020 lbs, Electro-plated

The B261-12ZN 45 degree knee brace is rated for 1020 lbs. That is the figure to design to when you are bracing a strut trapeze or a cantilevered strut arm against deflection, and it is why this part shows up on pipe and conduit support runs rather than light-duty shelving.

It fixes a 45 degree angle. The B261-12ZN is a two hole knee brace, so one hole bolts to the vertical strut and one to the horizontal, triangulating the corner at 45 degrees. If your connection needs to be adjustable or square, a knee brace is the wrong fitting for it.

Corner to brace length is 10-1/8 inches, so measure 10-1/8 inches out from the inside corner along each leg to pick up the brace holes. Overall the piece runs 12 inches long, 10.12 inches high and 1.62 inches wide, which is what you want to check against clearance behind ductwork or adjacent racks.

Electro-plated zinc on steel is a dry indoor finish. The B261-12ZN is fine in conditioned mechanical rooms, electrical rooms and above ceilings, but for roof decks, parking structures, wash-down areas or coastal exposure you want a hot dip galvanized or stainless knee brace instead.

The B261-12ZN ships as the steel brace only, at 1.65 lbs. Add two strut nuts and hex bolts sized to your channel, one set per hole, to complete the connection.

A 45 degree knee brace like the B261-12ZN triangulates a corner in the plane of the two strut members, so it stiffens a cantilever arm or an L-shaped frame against rotation at that joint. It is not a seismic sway brace assembly and it is not a substitute for engineered longitudinal or lateral bracing on a piping run. Use it where you need the corner held rigid at 1020 lbs of capacity; use a listed sway brace kit where a seismic detail is called out.