The Almen Gage and Almen Strip

Author:  Jack Champaigne
Source:  The Shot Peener magazine, Vol 04/Issue 1, Spring 1990
Doc ID:  1990152
Year of Publication:  1990
Abstract:  
After the discovery that surface treatment by blast cleaning caused significant fatigue resistance improvement, John Almen devised a scheme to provide process consistency. Intensity of the shot blast stream was deemed to be a dominant variable to be controlled. Measurement of this intensity was made, by implication, with a test strip made of the same material as the valve springs being treated (SAE 1070 RC 45-50). By blasting, and therefore stretching, only one surface of the test strip the resulting curvature could be used as a measure of blast intensity.