3.Pressure Angle(α): 14.5°-30° 4.Helix Angle(β): 0°-45° 5.Direction of Helix Angle: Left Hand/Right Hand 6.Accuracy: GB/T6082-2001 Standard Class AA/A/B 7.Notes: Our products can be titanized as customer's requirement We can provide all kinds of gear 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.