B-Line Eaton series imperial cable tray and ladder, 4" height, 91.11" length, 42" width, Series 2-5 horizontal bend, 90°, 12" radius, Aluminum

Yes, that is exactly what it is built for. The 4A-42-90HB12 is a Series 2-5 horizontal bend sized at 42 inches wide with a 4 inch side rail height, in aluminum, so it splices into a straight aluminum ladder run of the same 42 inch width and 4 inch loading depth. Mixing widths or rail heights at a bend means the rails and rungs won't line up at the splice plates, so keep the bend width and height identical to the straight sections it joins.

Plan for roughly 91.11 inches of overall length on the fitting, which is the dimension B-Line publishes for the 4A-42-90HB12. That comes from a 90 degree turn on a 12 inch inside radius across a 42 inch tray width, so the outside sweep is substantial. Lay it out on the deck or ceiling grid before you set the trapeze hangers, because a 42 inch wide bend eats far more corridor space than the straight run leading into it.

No. A horizontal bend turns the run left or right in the same plane, which is what the 4A-42-90HB12 does at 90 degrees on a 12 inch radius. To go up or over an obstruction you need a vertical inside or outside riser fitting of the same 42 inch width and 4 inch rail height, not a horizontal bend.

It is UL Classified, which is how cable tray is normally recognized rather than UL Listed. Inspectors reviewing a tray installation generally want the UL Classification on the tray and fittings plus a grounding path that meets the electrical code, so keep the bonding jumpers across the splice plates at the bend if the tray is being used as an equipment grounding conductor.

Aluminum is the material on the 4A-42-90HB12, and the practical payoff is weight and corrosion resistance. The fitting comes in at 18.944 pounds, which one person can set on a 42 inch wide run without a lift, and aluminum needs no galvanizing or paint in damp or coastal environments. Steel tray is the choice where you need higher rung load capacity or longer support spans, and it costs less per foot. Don't mix aluminum and steel at a splice without the correct hardware, or you'll set up galvanic corrosion.

Order the splice connectors separately. The 4A-42-90HB12 is the bend fitting itself, a Series 2-5 horizontal bend in aluminum, and cable tray fittings are normally supplied without the splice plates and bolt hardware needed at each of the two connection points. Add the matching aluminum splice plates, hardware, and any hold-down or hanger hardware for the support at the turn when you write the order.

The manufacturer part number is 4A-42-90HB12 from Eaton's B-Line series. The code reads out as 4 inch aluminum, 42 inch width, 90 degree horizontal bend, 12 inch radius, which is why the adjacent numbers change only in the width or radius digits.

Yes, support the fitting itself rather than relying on the straight runs either side. On a 42 inch wide, 4 inch deep aluminum bend spanning about 91.11 inches of length, the turn is where cable weight concentrates, so set trapeze or wall bracket supports near both splice points. The fitting's own 18.944 pounds is minor next to the fill it will carry.