These are some interior stairs I did today. They have a single stringer made out of 2 x 3 x .25 wall. The risers are made out of 1/4'' Plate and the treads are going to made from 5-1/8'' thick Glue lam.
SNOW is hear back to welding Aluminum snowmobile running boards, and seat frames. Check out there web site http://www.wr-products.com/ . We do all the bending and welding at 3X Specialties
My first time doing a spiral stair case. This one is a little different then most that get done hear at 3x Specialties. The difference is the top rail I started with one straight stick of 2"round tubing .120 wall and heated and formed it around. That alone took about 10 hours.