Effect of Cutting with an Abrasive Saw on Swarf Composition

Crime scene investigators are often asked to examine swarf from break‐in sites and compare it with swarf found on a suspect. Occasionally, elemental composition of swarf from these two sources does not match. It is generally assumed that cutting metal does not induce changes in chemical composition. However, this study shows that, if a matrix contains iron, chromium, and nickel, composition of swarf produced from cutting the matrix with an abrasive saw may indeed alter. In this study, we cut a stainless steel sheet using a standard cutoff saw. Swarf was sorted and chemically analyzed by EDS/SEM, and the following relationships between chip morphology and modified composition were discovered: elongated chips remained unchanged; changes in the irregular chips appeared to be random, possibly because they are formed in a number of different ways; composition of spherical chips changed with size.