Plug Chamfer - National Fine Fractional Machine Screw Sizes in a Index Case.  18 Pc. High Speed Steel 135° Split Point Gold & Black Drills & High Speed Steel Gold & Black NF Taps

Tap Sizes: 6-40, 8-36, 10-32, 12-28, 1/4-28, 5/16-24, 3/8-24, 7/16-20, 1/2-20 Drill Sizes: #33, #29, #21, #15, #3, I, Q, 25/64, 29/64