Machine Screw and Fractional Plug Taps. Precision Cut Threads, Accurately Formed For Consistent, Exact Threading. Heat Treated And Tempered For File Hard Threads, And Longer, Useful Life. Designed For Hand Cutting Applications. For Use With Tap Wrenches To Cut Internal Threads. 75% Thread Engagement. Plug Style Is The Most Commonly Used Style Of Tap -3 To 5 Threads Chamfered. Letter Gauge Drill Bits. Made From Premium Grade High Speed Steel. Precision Ground 118 Degree Points. Designed To Operate In Stationary Or Portable Tools. General Purpose Drilling In Wood Metal And Plastic. Letter Drill Bits.