Specification:Name: forty five Degree Helical GearModel: 1M (1 Module)Direction: Left Hand / Right Hand Material: 45# SteelSurface Treatment: BlackeningTooth Surface Treatment: High Frequency Quenching and HardeningTeeth: forty five TeethTooth Height: 12mmTotal Height: 22mmRound Bore: 8/10/12mmKeyway Bore:12mm-keyway 4x1.8mm 14mm-keyway 5x2.3mm 15mm-keyway 5x2.3mm 16mm-keyway 5x2.3mm 17mm-keyway 5x2.3mm 18mm-keyway 6x2.8mm 19mm-keyway 6x2.8mm 20mm-keyway 6x2.8mm Shaft Hole: Machining completedNote:1. The tools material is made of 45# steel, there could also be rust stains in case of water, which is normal and doesn't impact traditional use.2. Dimensions (such as bore size, whole thickness and different data) might range per the batch, please be successful in kind.Package :Packing : Plastic bag / Carton box.Quantity : According on your Choose!