Model: Spur GearMaterial: 45# SteelThickness 10mmTeeth Pitch: 3.14mmTooth depth: 2.25mmNote:1. The surface has now not been subjected to excessive frequency quenching2. made through gear shaping process, there will be a slight eccentric phenomenon3. Made of 45# steel, there could also be rust in the case of water, which is a standard phenomenon and won't affect common use.4. The inside gap is the method hole (hair blank hole) of the drill bit, with some deviation. diverse batchs, the internal bore might be a slight different.