How is Shot Peening Intensity Measured?

Shot Peening is often used to improve the performance of part, so it is important to ensure that the correct intensity is being created. This is achieved with the ‘Almen Strip’ testing procedure.

There are three basic types of Almen Stripes that are common in length (L = 3.00") and width (W = .75").

Type and Thickness of Almen Strips

• "N" Strip = .031"
• "A" Strip = .051"
• "C" = Strip = 094"

The strips are mounted into a Standard Hardened Block with four mounting screws to secure the Almen Strip. The shot is prevented from impacting the reverse side of the strip in order to achieve the "Arc-Height".

The effect of the induced compressive stress on the strip results in bowing or curving. The "Arc Height" is measured with the aid of an Almen Gage, after the strip is placed and retained magnetically against the bottom of the test fixture.