Manual measurement may have errors, please understand! For the usage of Morse taper shank, taper shank drills, reamers reducing.Adopts overall quenching process, long life, lasting, strong shock-resistance. High accuracy, inside and outside are very smooth. Easy to store and maintain, very useful. There may be some delays due to flight, holiday, weather, local post, local natural disaster impact. It must also be in the original packaging.