It was a typical Monday morning at the factory of Precise Engineering, a leading manufacturer of high-quality machinery parts. The production team was buzzing with activity as they prepared for another busy day. Among them was Jérôme, a seasoned quality control engineer, who was responsible for ensuring that all products met the company's stringent quality standards.
By invoking ISO 2768-mK, the designer communicates that all dimensions without specific tolerances must comply with the “medium” linear and “K” geometric limits. This drastically simplifies the drawing, reduces clerical errors, and streamlines the first-article inspection report. For the workshop, it signals a standard of good practice: the part must be reasonably flat, holes must be reasonably perpendicular to faces, and linear sizes must fall within typical milling or turning accuracy without secondary operations.
The standard represents the default "language of quality" for general machining.
When a drawing is labeled "ISO 2768-mK," it implies that any dimension lacking a specific tolerance label (e.g., $50^+0.1_-0.1$) automatically inherits the tolerances defined by the "m" and "K" classes. This is based on the premise that standard manufacturing processes can achieve these tolerances routinely without special attention.
Définit les tolérances pour les dimensions linéaires et angulaires (longueurs, diamètres, rayons) selon l' ISO 2768-1 .
ISO 2768 is divided into two parts: