Material: 45# steel Accuracy: 0.015mm, Hardness: 50 HRC Inside stepped No. * Outside taper No. * Outer diameter * Full length * Inner diameter: MT1 * MT2 * 18.6mm * 12.065mm * 90mm; MT2 * MT3 * 24.7mm * 17.78mm * 107mm, MT3 * MT4 * 31.6mm * 23.5mm * 132mm Package included: 3pcs Morse taper adapter