Toolmarks made by lathe chuck jaws

•A forensic method to evidentially tie a workpiece with a specific lathe.•This method, can prove or exclude a connection between workpiece and a specific lathe.•This method is based on comparing jaw impressions made by the chuck on a workpiece.

This paper presents a forensic method to evidentially tie a workpiece with a specific lathe. Examining using this method can prove or exclude a connection between the two. The importance of this method is mostly due to the growing trend among lawbreakers of manufacturing improvised firearm parts using machining processes. This method is based on comparing jaw impressions made by the chuck on a workpiece.