Mandrel No. 9 has a No. 5 screw thread, and a fixed shoulder flange. Maximum Safe Speed 25,000 Revolutions Per Minute with 1/2" overhang or less (exposed mandrel length). For each additional 1/4" of overhang the Maximum Safe Speed is decreased by at least 20%. For Point Nos. 11, 12, 14, 15.
