We run into this thing a lot, especially when quoting or building for the military ; they are rabid about knowing the materials' components plus where the actual materials of the parts came from - we require materials certifications, which nearly any manufacturer can supply - whether or not they are factual is another story but at least you will have done as much due diligence as possible. Most bearing manufacturers will give you more precise materials composition - I'm surprised you're getting answers like 'steel'. I'm hoping I'm on the right track with this answer - it's predicated upon the assumption that you are buying an already- produced bearing? If you are having bearings made specifically for your project, your foundry will be able to give you exact materials specs and provide you with upgrade alternatives. That's a given with them - if they give you a hard time, get another foundry.

I hope this helps.

ps. to answer your last question, I don't think it's a standard industry response but much depends upon who's answering the question. I do know that a lot of sales reps simply don't know the composition of a lot of what they are selling - but they can find out. I force my reps to FIND OUT! Or send me to tech. Or something. Techs should also be able to advise you on tolerance variations re the particular materials in question. 'Steel' is not an acceptable answer!