This process shaved the journals leaving a margin of finishing.
This process shaved the weight part coarsely, and shaved the pins leaving a margin of finishing.
In order to make it the form of a crank shaft, the outside portion of weight and superfluous portion are shaved.
Internal stress is removed, the structure is stabilized and hardness is set to HRC 28-32.
This process shaved the journals leaving a margin of polishing.
This process shaved the pins leaving a margin of polishing
This process made the oil holes, the key slots, the pulley bolt holes, and the flywheel bolt holes.
This process polished the journals and the crank pins.
In order to suppress oscillating of a crank as much as possible, the balance of a crank simple substance is measured and balance processing is performed.
This process is to improve the degree of true circle and surface roughness in order to gain smooth rotation and reduction of friction.
Surface strenth, durability of friction, and fatigue strength of the surface are improving. The surface becomes black by the surface treatment. (There is effect which helps early fitting.)
After the last wrapping, the bend which causes vibration is corrected. It is inspected after bend correction.