input: [0] Pinion Shaft [1] 1 [2] 1 [3] Takes the energy provided by the motor and distributes it to the saw blade. Transfers energy through the use of gears. [4] Steel [5] Relatively cheap, steel is needed due to its strength and durability. Plastic is not recommended here. [7] Necessary for the desired properties of this part. Relatively cheap. [6] 
output: Steel is first extruded and secondly given teeth. Ends forged for strength