4.Pressure Angle(α): 14.5°-30° 5.Helix Angle(β): 0°-35° 6.Direction of Helix Angle: Left Hand/Right Hand 7.Accuracy: GB/T14333-93 Standard Class A/B 8.Specifications(mm): NominalPitchCircleDia.:180mmβ5°α20°ModuleNo.ofTeethOutsideDia.HoleDia.1.25115149.2563.51.5115178.661.75100181.73283171.722.2573170.522.567174.322.7561175.13353167.313.2553181.953.547175.733.7543174.01441177.734.537182.14531173.495.529179.71627184.32 We can provide all kinds of geaer hobs, gear shaper cutters and gear shaving cutters. If you have any requirement, pls contact us. We'll try our best to satisfy you. You're welcome every time, all the time.