Beware the Dodecahedron

Author:  Joe Simmons (Hartzell Propeller Inc)
Source:  The Shot Peener magazine, Vol 26 / Issue 2, Spring 2012
Doc ID:  2012016
Year of Publication:  2012
Abstract:  
HARTZELL PROPELLER recently had an unusual experience that highlights the importance of defining appropriate media shapes. We think our findings will be helpful to everyone that buys, inspects and uses media and are worth consideration by members of the shot peening sub-committee of Aerospace Metals Engineering Committee (AMEC). This AMEC group is responsible for creating and updating the shot peening specifications used in aerospace. A Process is Developed It started when one of our propeller repair stations ordered a batch of conditioned cut wire shot. The media was shipped with certification for AWS-62 per AMS 2431/4. The media passed the repair station’s receiving inspection and went on to their new shot peening machine. The media went into the machine, setup work began, and a process was developed. After the sample process was completed, the repair facility sent us a package for audit with a copy of the media certification, a set of Almen strips and an overhauled aluminum scrap part.