The DeWalt DW4809 8-Inch 14 TPI Straight Back Bi-Metal Reciprocating Saw Blade is a tough blade that's built for cutting in heavy-gauge metal, hard rubber, fiberglass, and angle iron. This straight-back blade can also be used to cut a wide variety of materials, including wood, plastic, and drywall. In general, a lower tooth count cuts faster, but provides a rougher finish, and this 14 TPI (Teeth Per Inch) blade is no different.