APPLICATIONS OF THE ULTRASONIC SERIAL NUMBER RESTORATION TECHNIQUE TO GUNS AND TYPICAL STOLEN ARTICLES

摘要

An ultrasonic cavitation method for restoring obliterated serial numbers has been further explored by application to articles involved in police cases. The method was applied successfully to gun parts. In one case portions of numbers were restored after prior failure by other laboratories using chemical etching techniques. The ultrasonic method was not successful on a heavily obliterated and restamped automobile engine block, but it was partially successful on a motor-cycle gear-case housing. Additional studies were made on the effect of a larger diameter ultra sonic probe, and on the method's ability to restore numbers obliterated by peening.