One steel section that does not typically come as a profile from a steel mill is the tee section. Except for small sections, steel tees are produced by splitting beams. A rotary shear or a torch cuts the web of the beam to produce two tees. The cut is usually down the middle of the beam but sometimes is done off center.
When the residual stresses of the beam are released by cutting it, the tees take the shape of a banana. If straight beams are required, then a straightening operation must be done. One method is to press the beams in a cambering machine which restrains the steel section while being pressed with one or two hydraulic cylinders. Another method is to roll the beam sections on an angle roll (also called a section bender or profile bender). The latter method tends to produce a straighter tee.
21in tees up to 80ft long with up to 1in web thickness can be produced. The standard tolerance for tees is 1/8in over 5ft; with the right angle roll, the tolerance can be as precise as 1/8in over any length of tee. Tees 30ft long can be rolled to within 1/16in overall.
After beams have been split into tees, the tees can be curved with the stem in, the stem out, or the stem up, to both large and very tight radiuses and everything in between. And again, to very precise dimensions.