Jae these were the dimensions given on a material list, I have tried to see if steel beams were measured differently then other materials but I cannot find any info. I think 14w is the flange size and the rest is width and length
OK that makes sense....in that case it would theoretically be a W12x48 (or is it W14x48??? you used both)
There historically have been very few 12" beams at 48 pounds per foot - just some old Bethlehem shapes from many years ago. There are currently W14x48 sections rolled.
The 58-2 would perhaps be the length of 58'-2".