Bosch T121AF3 3-Piece 3-5/8 In. 21 TPI Speed for Metal T-Shank Jig Saw Blades For sheet metal 10-16 gauge and thin metals 1/16 In. to 1/8 In. thick (ferrous and non-ferrous) 21 TPI with unique tooth geometry including rigid and aggressive profiles for unrivaled speed in metal cutting Backward taper design simulates pendulum motion to increase speed Bimetal construction for durability and long life 3-5/8 In. overall length, 2-5/8 In. working length