/ Precision Measuring Tools / Precision Hand Tools / Fixed Gage Standards / Angle Gages / C391 * Not actual product image 51475 C391 Center Gage 51475 Other similar products The Starrett C391 Center Gage features inch graduations, meets the American Unified National Standard and US 60 degree standards. American unified National Standard, 60 Deg. Features Specifications Contact Starrett Features Extremely handy for use in grinding and setting screw cutting tools American National or U.S. 60 Deg standards Very useful for finding number of threads per inch through graduations in 14ths, 20ths, 24ths and 32nds of an inch. Gage also has a table of double depths of threads for determining size of tap drills. Made of spring-tempered steel with satin chrome finish. Ground gaging surfaces Specifications Range (Deg): American Unified National Standard, 60º Material: Steel