HSS Titanium Coating: The hex bits feature titanium-coated high-speed steel for added wear resistance and durability. The is hardened and ground for sharpness, suitable for wood, aluminum alloy, stainless steel, plastic, etc. Fluted Form and 135 Bifurcation Point: The 135 bifurcation point makes drilling easier with less pressure and prevents the bit from walking. Dual U-shaped effectively remove chips, reducing friction and heat for a faster, cooler drilling process. Quick change: 1/4inch hex is compatible with power screwdrivers, impact drivers and other tools that accept 1/4inch hex , eliminates frustration with spinning in chuck, easily locks into chuck without slipping out and fall off. Size: 13 different sizes including 1/16inch, 5/64inch, 3/32inch, 7/64inch, 1/8inch, 9/64inch, 5/32inch, 11/64inch, 3/ Available in 16inch, 13/64inch, 7/32inch, 15/64inch, and 1/4inch, each bit has a designated hole in the bit holder with a size index for easy storage and quick organization. Colour: Material:HSS Size:16 x 16CM Package Contents: 13 x Titanium drill head Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.