What is the OD of the main housing on most BT30 spindles? I'm asking because my main bearings are pushing me for a big housing. The bearings are 75mm OD so when I cut the housing 90mm then I'll have 7.5mm wall. And I'll drill 6x 4mm threads for the outer part of the labyrinth seal. So that the 6 holes will be weak points. In short I have 2 choices: 90mm or 95mm housing. Please see the attached render. What do you think?
Another question: is stainless steel acceptable for the housing?