A replacement blade for PORTER-CABLE® model 557, this rugged blade has 6 strong carbide teeth for reliable, consistent cuts with every pass. It features a 7/8 in. arbor hole and 4 in. diameter blade for rapid and efficient cutting of standard biscuit slots without sacrificing precision or control. To help reduce future replacement costs, this blade can be re-sharpened. It affixes and detaches with minimal effort. This is an O.E.M. authorized part. Fits various PORTER-CABLE® models. And, its made in the USA with global materials.