Since being founded in 1941, every tool that has been produced by Grace USA has undergone a rigorous inspection process which helps ensure genuine QUALITY and PRECISION in every tool that you can TRUST. This set is built for precision and includes the following Star Head Screwdriver Sizes: T5, T6, T7, T8, T9, T10, T15, T20, T25, T27, and T30. The square shanked blades are hardened to R/C 52-56 and constructed of USA 8650 Chromium-Vanadium steel alloy with a black oxide finish while backed by our Forever Guarantee not to twist or chip. A TRADITION OF EXCELLENCE SINCE 1941: Since being founded in 1941, every tool that has been produced by Grace USA has undergone a rigorous inspection process which helps ensure genuine QUALITY and PRECISION in every tool that you can TRUST PRECISION FOR THE PERFECT FIT - EVERY TIME: This set is built for precision and includes the following Star Head Screwdriver Sizes: T5, T6, T7, T8, T9, T10, T15, T20, T25, T27, and T30 BLADES THAT ARE BUILT TO LAST: The square shanked blades are hardened to R/C 52-56 and constructed of USA 8650 Chromium-Vanadium steel alloy with a black oxide finish while backed by our Forever Guarantee not to twist or chip A HANDLE YOU'LL ENJOY HOLDING: Our screwdriver handles are turned to our exact specifications using Maine hardwood, delivering a strong, non-slippery grip - even when your hands are oily. The handles are topped off with a nickel-plated steel ferrule CRAFTED FOR MANY APPLICATIONS: While our screwdrivers were constructed as the ideal tool for gunsmithing, they also can be used for woodworking, industrial, military, mechanical and home care needs