Designed by Brain Brazeal, this is the most efficient cutting hardy I know of. The cutting hardy is the most essential hardy tool! The tapered shank fits a few different sizes of hardy holes from about 3/4 inch to one 1-1/8, and is perfect for a 1 inch hardy hole in particular. Made from 4140, and not heat treated because this tool is only meant to be used with hot steel. Contact me for any questions, or check out the “FAQ” page.