Descript ion: These adapters are m ade from high quality steel, hardened and tempered, precision ground inside and outside for high concentricity. T aper shank allows the tool to be inserted directly into the machine's spindle to facilitate high-torque applications such as large cut diameters. Features: Ma de from high qua lity 45# steel, durable, we ar-resisting and long service life . Ado pts overall quenching process, strong shock-resistance . Hig h accuracy, fine workman s hip, in side and outside are very smooth . Ea sy to store and ma intain , very useful. There are 4 types for your choice . Fo r the usage of taper shank cutter, taper shank drills, taper shank reamers, improving work efficiency . Specifications: Material: 45# steel Type: MT1 to MT2, MT2 to MT3, MT3 to MT4, MT4 to MT5(Optional) Hardness: 50 HRC Type D(mm) d(mm) L(mm) External Taper (MT.NO.S) Internal Taper (MT.NO.T) Inner Hole Length(mm) Weight(g) MT1 to MT2 17.78 12.065 92 2 1 56 89 MT2 to MT3 23.825 17.78 112 3 2 67 174 MT3 to MT4 31.267 23.825 140 4 3 84 350 MT4 to MT5 44.399 31.267 171 5 4 107 1000 Package Included: 1 x Taper Drill Sleeve Note: Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.