High tensile steel is a very general term. More specific, but still general terms would be Low/Mid/High Carbon steels.

For speeds/feeds you really need to know the exact grade and current state (i.e. annealed, hardened, tempered - bigger sized bars in certain grades can have varying states of hardness/temper as you move from the perimeter to centre).
A good start for speeds/feeds, is to use a speed and feed calculator, which should give you some reasonable numbers to start with. A good online calculator is FS Wizard - http://zero-divide.net/index.php?page=fswizard