Shot Peening

Shot Peening in Minneapolis


Shot peening is a cold working process in which spherical media called shot is propelled at the surface of a component to impart compressive stresses and incrase fatigue life.


During the shot peening process, each piece of shot that strikes the material acts as a tiny peening hammer, imparting to the surface a small indentation or dimple. To create the dimple, the surface of the material must yield in tension. Below the surface, the material tries to restore its original shape, thereby producing below the dimple, a hemisphere of cold-worked material highly stressed in compression.


Nearly all fatigue and stress corrosion failures originate at the surface of a part, but cracks will not initiate or propagate in a compressively stressed zone. Because the overlapping dimples from shot peening create a uniform layer of compressive stress at metal surfaces, controlled shot peening in Minneapolis provides considerable increases in part life. Compressive stresses are beneficial in increasing resistance to fatigue failures, corrosion fatigue, stress corrosion cracking, hydrogen assisted cracking, fretting, galling and erosion caused by cavitation. The maximum compressive residual stress produced just below the surface of a part by shot peening is at least as great as one-half the yield strength of the material being shot peened.


In most cases of long-term failure, the common denominator is tensile stress. Tensile stresses attempt to stretch or pull the surface apart and may eventually lead to crack initiation. Shot peening helps slow crack growth significantly in a compressive layer. Shot peening is the most economical and practical method of ensuring surface residual compressive stresses.


Shot peening services in Minneapolis is always associated with a specification that is like a recipe for shot peening. These are developed by engineers during the initial production of parts and must be adhered to during the peening process.


Eaglemaster Inc has several machines available for controlled shot peening services in Minneapolis with different sizes of shot for various applications. Shot peening can be a difficult process to understand but Eaglemaster Inc can help with our expertise and experience.


  • Increase fatigue life for high stress components
  • To adhere to print or engineering specifications
Work with Eaglemaster Inc. on your next deburring or metal finishing job. Get in touch for a quote and free sampling!