B-Line B115SS4 Eaton series strut fittings and accessories, 3.93" Height, 3.75" Length, 1.62" Width, .76lbs, Steel, Pre-assembled fitting, Four hole adjustable corner angle, 90 deg, Thickness 1/4 in, Stainless steel type 304

The B115SS4 is a four hole adjustable corner angle for joining strut at a 90 degree corner. It ships pre-assembled, so the two legs come already put together and you bolt it into the channel rather than building the joint up from loose pieces. Four bolt holes means two fasteners per leg, which is what keeps the corner from racking under load.

It is Type 304 stainless steel, which is the grade contractors normally use for exterior, damp, and wash-down work where plain electro-galvanized fittings would rust out. For heavy chloride exposure, coastal spray or pool chemical rooms, 316 stainless is the usual step up from 304.

The material is 1/4 inch thick. That is a heavy-gauge fitting, not a light bracket, so it suits structural strut corners carrying conduit racks, trapeze supports, and equipment frames rather than light signage or shelving work.

The fitting itself arrives pre-assembled, but the bolts and channel nuts that fasten it into the strut are separate items. Order them to match: if you are putting a 304 stainless angle on the job, use stainless channel nuts and bolts too, since mixing plated steel hardware into a stainless assembly puts the corrosion right back at the joint.

The manufacturer part number is B115SS4, from Eaton's B-Line series of strut fittings. The SS4 on the end is the Type 304 stainless version, so quoting the full part number is what keeps a plated-steel equivalent from being substituted on you.

A four hole 90 degree corner angle like the B115SS4 is for turning out of plane, tying one run of channel to another at a right angle with two bolts per leg. A flat plate only joins strut in the same plane, so it will not make the corner. If the two runs meet in one plane, a flat corner or tee plate is the right part; if they turn a true 90, use this angle.