16 Shape: S3< Reference circle diameter (mm): φ8 Tooth width (mm): 4 Module: 0.5 Hole diameter A (mm): φ2 Tooth tip circle diameter: 9 Total length (mm): 7 Hole diameter A' (mm): φ2.1 Boss diameter (mm): 9.4 Tooth tip circle diameter (mm): φ9 Boss length (mm): 3