1.Material: HSS or carbon steel. 2.Black chamfer drill body material: steel 3.Special designed steel counter sleeve countersinks or counter bores pilot hole. 4.Adjustable counter sleeve depth with wrench. 5.Drilling length can be adjusted for various length screws simply by loosening and tightening the setscrew. 6.Single Flute edge chamfer 90 Degree 7.Great drill accessory for any work shop backed by manufacturer's lifetime warranty 8.Heat treated & tempered high-carbon steel with Titanium Nitrate coating for superior cutting power 9.Use on steel, aluminum & other metals, plastic or wood Enlarge or countersink holes, deburr edges; 15-degree chamfer.