Hougen Holcutters Holcutters are not hole saws - they are precision ground; heat treated tools that easily cut through materials rather than ripping; tearing; and pushing like a standard hole saw They produce holes three times faster and cleaner than hole saws in sheet metal and dramatically extend the life of the tool in which they are used All sizes have a inshoulderin to prevent the bit plunging through the material being cut; - very useful for cutting holes in live electrical boxes Holcutters dramatically outlast bi-metal hole saws and step drills For material up to 1/8 thick Use with Holcutter Arbor 14009" Hougen Holcutter 2-1/4" Sheet Metal Hole Saw 14268