– Professional grade Bi-Metal hacksaw blade.s – 12″ length, 24 teeth per inch (TPI) x 10. – BI-METAL construction allows blades to bend and flex without breaking. – Blades made in high speed steel (HSS) teeth with wavy set. – 3X SHARPER and last 15X LONGER than normal blades. – Suitable for use on different material including wood, PVC, copper tubes, aluminum pipes, steels, ets.