You will need to add an orientation constraint. Basically you can assemble a bolt with an axis and a plane, or insert and plane. Pro-E with add the assumptions and say fully constrained. What you will need to do is add another constraint and choose the planes on both parts. Then select the angle you need it to be, i.e. 90 degrees. The other choice is to choose the plane that is already 90 degrees from the other plane. Eric