The Fishtail Center Gage is a useful guide for grinding and setting thread cutting tools with a grinder or lathe. Made of hardened steel with a satin chrome finish, the Center Gage is graduated in 14ths, 20ths, 24ths and 32nds for the accurate measurement of threads per inch. The Center Gage also indicates double depths for use when determining the size of a tap drill. Determine proper angles for grinding screw cutting tools. Can be used with a lathe or bench grinder. Improve efficiency and lessen setup time. Graduations in 14ths, 20ths, 24ths and 32nds of an inch. 60 degree angles for use with U.S. Standard threads. Double depth of American National threads. Clearance slot in notches.