Almen Strip Specifications

Author:  Jack Champaigne
Source:  The Shot Peener magazine, Vol 11/Issue 3, September 1997
Doc ID:  1997048
Year of Publication:  1997
Abstract:  
A Brief History of the Almen Strip Since the invention of the Almen strip and Almen gage by J.O. Almen in 1942 the shot peening and blast cleaning industries have had a simple, inexpensive and reliable tool to gage shot blast stream intensity. Basically, the Almen strip is a small (3 inch by 3/4 inch) piece of spring tool steel that is blasted on one side and made to curve in response to the intensity of the impinging blast stream. The original strip thickness was 0.050 inch and had no letter designation until the "B" strip was developed. Although there doesn't seem to be any remaining records of the "B" strip, it can be surmised that it was quickly replaced by the "C" strip with thickness of 0.094 inch for higher intensity applications of the automotive sector. (It's not clear when the "A" strip thickness changed from Almen's 0.050 inch patent to the present value of 0.051 inch.)