Description: These adapters are made from high quality steel, hardened and tempered, precision ground inside and outside for high concentricity. Taper shank allows the tool to be inserted directly into the machine's spindle to facilitate high-torque applications such as large cut diameters. Features: Made from high quality 45# steel, durable, wear-resisting and long service life. Adopts overall quenching process, strong shock-resistance. High accuracy, fine workmanship, inside and outside are very smooth. Easy to store and maintain, very useful. There are 4 types for your choice. For 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.