Spring-Loaded and Spring Centered Tap Guides The spring-loaded tap guide has a 3/16-inch diameter, hardened tension pin that is adjustable. This pin is also reversible for male and female hole centering or tapping. This guide also has a 1/2-inch diameter hardened shank that is knurled for batter grip. Start every tap straight with this tool. The spring-centered tap guide also has a 1/2-inch diameter hardened shank. This tool is used to align taps for threading, lathes, mills and jig bores. It can also be used with drill chucks to stroke the hardened point for accurate hand tapped threads. The point on this guide is hardened up to 50-55 HRC. The center's body should be gripped in a drill chuck or collet while the hardened point is inserted into the middle of the tapping handle. The stroke of the center will follow the tap assuring straight and accurate hand tapped threads. It is a universal size for all tapping applications.