ABSTRACT
Serial numbers are mostly observed on the surfaces of iron, steel and metallic alloys. Such kinds of serial numbers in the form of alphanumerical codes are obliterated to conceal the identity of the materials by various methods. The decoding or restoration of erased numbers from the surfaces is one of the main challenges in criminal investigation and quite difficult to restore on tougher obliterations. However, deciphering the obliterated unique codes using chemical reagents (chemical etching) has been proved of its ability to deciphering the mechanical erasures. Here in this study we discuss about the ability and effect of particular chemical reagent on the iron, steel and aluminum-alloy surfaces. Such types of metallic surfaces have been proved of various applications in chassis of motor vehicles, railway iron rods, engine parts etc. The chemical reagent’s properties on obliterated metal surfaces were studied using different types of Fry’s reagent (Table1-4). Hence this study may have application relevance in criminal investigations involving erasures of identity serial number. key messages: The author(s) tried to include scientific explanation restoring serial numbers on iron and steel surface using chemical etching process and some challenges.