Yes, I put a roll pin in one motor doing exactly that
However, after trying many things I recommend this way if you have space for the bolthead. It is better.
@MysticalDork is correct, they are case-hardened and they are situated next to soft aluminum. The only way I can make a hole in that with with a carbide endmill. You have to be careful or it will just walk over into the aluminum. You CANNOT use a drill bit.