Abstract 

Purpose – The purpose of this paper is to outline and document the failure root cause of a carbide cutting tool during machining of a hardened tool steel under automatic machining conditions. Design/methodology/approach – Optical metallography and SEM/energy dispersive spectroscopy analysis, together with optical profilometry were employed for failure investigation. The use of an alternative cutting tool andmodification ofmachining conditions are proposed as a failure preventive action. Findings – Severe abrasive wear and adhesion of machining chips are observed in the flank zone, causing blunting of the cutting edge. The revision of cutting conditions, together with the use CBN-based tool insert leads to an overall improvement of the stability of the process and tool lifetime. Originality/value – This paper places emphasis on a failure analysis case history following a structured approach in industrial machining problem solving, highlighting suggestions for process improvement.