Kobe Steel, Japan’s leading steelmaker, says it will develop a new forging process for maritime crankshafts that will improve fuel efficiency by 9% during sea trials. Crankshafts connect to the pistons of an engine and rotate when the pistons are fired, which turns the shaft that drives the propeller. The new process involves the stamping of heated iron into metal molds to make lightweight, yet higher strength, crankshafts. Kobe Steel says the process improved resistance to metal fatigue by 20%. It has been known that lighter crankshafts with larger radii increase fuel efficiency, but until now they have been difficult to manufacture. Conventional crankshaft forging processes leave stress points along the shaft, making them less durable.