B-Line Eaton series imperial cable tray and ladder, 4" Height, 48" Length, 18" Width, 18" and 12" Tray widths, Series 2-5 horizontal cross, Aluminum,

Model 4A-18-12-HX12 is a Series 2-5 horizontal cross built for 18 inch and 12 inch tray widths, so it joins a run of 18 inch tray with 12 inch branches at a four-way intersection. The body itself is 18 inches wide with a 4 inch side rail height. If your branch runs are a different width, this is the wrong fitting - the width combination is fixed in the part number.

It is a 12 inch radius fitting. That radius sets the minimum bend the cable sees turning through the intersection, so it is the number to check against the minimum bending radius your cable manufacturer specifies. If your conductors call for more than 12 inches, you need a larger radius cross, not this one.

Use a cross where four tray runs meet at one point in the same horizontal plane, which is what the 4A-18-12-HX12 is built for. Two tees back to back leave a short straight section between them and add extra splice joints, plus the branch centerlines end up offset rather than in line. If only three runs meet, a horizontal tee is the correct fitting instead.

Working dimensions are 4 inch height, 48 inch length, and 18 inch width, with a 12 inch radius on the turns. Deduct that 48 inch overall length from your straight tray sections when you take off the run so you are not short-cutting or field-trimming a section at the intersection.

The fitting weighs 16.088 lb bare. That is the dead load before cable fill, so size your trapeze or threaded rod supports for the loaded weight at the intersection, not this figure alone.