This HTC A-28X10555 is a high-quality end mill made of durable M7 It features a square end mill design with two flutes and a mill diameter of 7/8 inches. The shank diameter is 3/4 inches, and the overall length is 4-1/8 inches, the Helix angle is 37 degrees. This end mill is perfect for use in metalworking applications, Its brand, HTC, is known for producing top-quality metalworking supplies. With its square end mill design and two flutes, this end mill is perfect for cutting through Aluminum .