HHIP 7/8" Arbor X 3/4" Straight Shank Stub Mill Arbor Made of 40Cr steel known for its good hardenability, strength and toughness. Fits into standard end mill adapters. Furnished with standard keyways and left-hand arbor nut. Length of shoulder to nut is 1". Diameter of arbor is 7/8". Overall length is 111.9mm.