Excellet Quality: These drill bits are made from high speed steels and are available in 6 different diameters of 1/4 '', 5/16 '', 3/8 '', 1/2 '', 5/8 ' ', 3/4' '. NOTE: We have our own factory to produce this drill bit and can offer the best and quickest response to any problem or question you come across. Perfect Design: Five-blade chamfering with a groove, easier to discharge debris, and the high carbon steel bit is not easy to blunt. 1/4 '' hex shank cutters are suitable for a fast drill and do not slip in the chucks. eliminates burrs and vibrations: All have 90 ° angles on the precise and precise milling point. The cutting edge is sharp and hardened for sharpness. A five-tooth burr-free design with offset cutting teeth contributing to free chip flow and quick chatter free cutting. Widely Application: Ideal for wood openings, reaming, chamfering and so on. Also applies to wooden planks, MDF, plywood, fiberboard, acrylic, PVC board and soft metal such as aluminum, copper and so on. Warm Tips: You can easily make deep countersinks by adjusting the cutter depth stop to allow the cutter to drill deeper into the work surface. Remember to measure the size of your cap to make sure the body of your straw is on us first if you need any help during the operation, we will offer help ASAP. Package includes: 1 x 1/4 inch drill 1 x 5/16 inch drill 1 x 3/8 inch drill 1 x 1/2 inch drill 1 x 5/8 inch drill 1 x 3/4 inch drill 1 x automatic central punch