An experimental investigation of parameters influencing edge wear of magnetic recording tape during its passage through a magnetic transport has been conducted. Critical conditions of velocity (Vc) and load (Wc) are seen to exist, below which edge wear is negligible, but above which edge wear is excessive due to frictional heating. This transition from mild to severe wear can be represented by the general form WcVc2 = C, where the constant C depends on the thermal conductivity of the material in sliding contact with the tape. Theoretical calculations of the interfacial temperature, based on an extension of existing theory to account for multiple contacts and variable material properties, were in excellent agreement with temperatures which would cause plastic flow of the tape. © 1971.