Shot Peening Machine

Shot peening is an engineered blasting operation designed to propel industrial steel-shot media against the surface of steel parts to increase material strength and to reduce failure of critical parts under duress, such as the valve springs in cars or the landing gear in aircraft. “Peening” is a Scandinavian term meaning “to beat-out,” and metalworkers in the past used ball-peen hammers to condition their metal work to make it stronger. Today, with shot peening machines, thousands of tiny ball-peen hammers in the form of shot-peening media barrage and hammer the surface of metal parts within minutes, to render the metal stronger and able to resist surface stress cracking. Shot peening machines add remarkable speed and consistency to this process that once took days to complete – either reducing the amount of time necessary for the peening operation or enabling many more metal elements to be treated by shot peening machines during a standard work shift.

Shot peening is a cold-work method that involves pelting the surface of a metal part with round metallic shots that hit at high velocity. Within shot peening machines, each shot acts as a tiny “peen-hammer” that dents or dimples the metal’s surface and stretches it radially as it hits. The shot’s impact causes a flow in surface fibers that extends below the surface to the depth of impact – typically between .005 to .030″. Fibers beneath the top layer retain their elasticity. As a result, the shot-peened surface stays resilient and resists cracking when strained by heavy loads. Almen strips, (pictured below – left) are attached to the metal surface being shot-peened. These special metallic strips register or record the impact of the shot media so that the depth of the impact and the saturation coverage on the metallic surface can be monitored and ensured for accuracy and full coverage.