Metrology of Almen Arc Height Measurement

Author:  Dr. David Kirk, Honorary Research Fellow at Covent
Source:  The Shot Peener magazine, Vol 22 / Issue 2, Spring 2008
Doc ID:  2008009
Year of Publication:  2008
Abstract:  
Academic Study Dr. David Kirk INTRODUCTION Almen arc height measurement is very important to the shot peening industry. The primary application is for determining acceptable shot peening intensity which uses ferromagnetic steel (SAE 107) strips. A secondary application, using paramagnetic aluminum alloy (2024-T3) strips, is for ensuring that excessive intensity is not applied during aircraft paint stripping procedures. The mechanics of Almen arc height measurement are very well documented. Almen strips, holders and measurement gage requirements are rigorously specified. This article deals with the metrological principles of arc height measurement. The basic measurement components are the dial gage, strip holder and strip. Attention is focused on the significance of hold-down forces and ball wear.