YG-1 Spiral Point Tap, High Performance Square Shank, Series: I0 Series, Measurement System: Imperial, 0.2045 in, UNC, 1/4-20, 4P-5P Plug Chamfer, 3 Flutes, HSSE-V3, Steam Oxide, Class of Fit: 2/3B, 0.591 in Thread Length, 2-1/2 in Overall Length, 0.255 in Shank Dia, Medium to High Carbon Steel, Low Alloyed Steel, Free Machining Stainless Steel, Low Carbon Steel, Free Machining Carbon Steel, Pure Aluminum, Aluminum Alloy, Pure and Alloyed Copper, Free Machining Brass, Alloyed Brass, Zinc and Magnesium Material Application, H3 Thread Limit