This work presents an interactive self-learning tool named Technical Drawing Learning Tool-Level 2TDLT-L2for teaching manufacturing dimensioning to engineering students. The tool was designed for the students enrolled in the first year of the Bachelor in Management and Mechanical Engineering of the Universities of Brescia and Udine. It consists of a simple interactive tool, based on video and drawing animations, aimed at demonstrating the connection between real and simple machining processes and workpiece dimensions on technical drawing. TDLT-L2 is currently available in two versions: as a standalone application for Windows or Android based operating systems and as a set of interactive PDF documents. It was conceived as the first module of a package of tools that will be developed, based on the learning levels proposed in the Technical Drawing Evaluation GridTDEG. A preliminary evaluation of TDLT-L2 effectiveness was done involving the Management and Mechanical engineering students of Udine in some dimensioning exercises. The statistically considerations done on the obtained results confirmed the validity of the tool as a self-learning instrument with an average increase of marks of about 8.8%. (c) 2016 Wiley Periodicals, Inc. Comput Appl Eng Educ 24:519-528, 2016; View this article online at ; DOI