B-Line B104HDG Eaton series strut fittings and accessories, 4.12" Height, 4.12" Length, 1.62" Width, .78lbs, Steel, Pre-assembled fitting, Four hole corner angle, 90 deg, pre-assembled, Hot-dipped galvanized

It's a four hole corner angle that joins two runs of strut at 90 degrees. Two holes land on each leg, so each side of the joint gets a pair of fasteners instead of a single bolt, which resists the fitting rotating under load. It ships pre-assembled, so it comes out of the box ready to bolt up.

Yes. It's steel with a hot-dipped galvanized finish, which is the finish specified for exterior, wash-down, parking structure, and other wet or corrosive locations. Plain electro-galvanized fittings are the indoor-only option.

No. The B104HDG is supplied as a pre-assembled fitting only, so order your strut nuts, hex bolts, and washers separately and size them to the hole pattern in the angle. On a four hole corner you need four sets, two per leg, to make the connection as intended.

A two hole angle puts one fastener in each leg, which lets the joint pivot slightly and is fine for light bracing. The four hole version, like the B104HDG, doubles that to two fasteners per leg, which locks the 90 degree geometry and is what you want at a load-bearing corner, a trapeze knee brace, or a rack upright where the angle is holding the frame square.

Order it as B-Line B104HDG. The HDG suffix is the hot-dipped galvanized finish; the same base fitting exists in other finishes, so drop the suffix and you may get an indoor-only version.

Mechanically yes, the fitting bolts to standard strut regardless of the channel's finish. But if the run is outdoors, pairing a hot-dip fitting with indoor-grade electro-galvanized strut means the channel corrodes first, so match the strut finish to the environment rather than to the fitting.