Stone Tools ST-67 3-5/8-Inch Variable Pitch M-42 Bi-Metal Hole Saw<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>Uses M-42 tool steel as it's cutting edge</li><li>M-42 tool steel contains 8-Percent cobalt and 5-Percent tungsten for tough wear resistant teeth</li><li>Aggressive cutting action， especially for hard materials</li><li>Fast， smooth cuts with less vibration</li><li>Made in U.S.A.</li></ul></div><img src="http://ecx.images-amazon.com/images/I/41zMBf9xO1L.jpg" noproxy>