Cat. No. 48420101 is for Steel to 1/8", non-ferrous metals to 1/4", plastics, asbestos, fiberglas, rigid conduit, hard rubber and fiber.
Cat. No. 48420120 is for Metals 18 gauge to 10 gauge, tubing and plastics.
Cat. No. 48420140 is for Metals lighter than 18 gauge, thin wall tubing, slate and formica.