The designation is a combination of two distinct parts of the standard. Because ISO 2768 is split into two functional sections, the suffix "mK" tells the manufacturer which tolerance class applies to both linear dimensions and geometric deviations.
Table 1: Permissible deviations for linear dimensions (except broken edges) . Tolerance Iso 2768 Mk Pdf
High precision is expensive. "Medium" tolerances (mK) are usually achievable with standard CNC machining without specialized, high-cost, high-precision operations. The designation is a combination of two distinct
The "m" in mK defines the allowable linear and angular deviation. According to SogaWorks , "m" typically allows for a moderate range of deviation, such as a 0.3mm tolerance on certain hole diameters (depending on the dimension range). Table: Linear Dimensions (ISO 2768-1:m) Dimension Range (mm) Tolerance Class m (Medium) Over 3 to 6 Over 6 to 30 Over 30 to 120 Over 120 to 400 Over 400 to 1000 Table: Angular Dimensions (ISO 2768-1:m) Range of Length of Shorter Side (mm) Tolerance Class m (Medium) Over 10 to 50 Over 50 to 120 Over 120 to 400 4. ISO 2768-2:K (General Geometrical Tolerances) High precision is expensive
: For a nominal length of 30mm to 120mm, the "m" class allows a deviation of 2. ISO 2768-2 (Part 2): The "K" Class This part focuses on geometrical tolerances
Represents the "K" class for geometric features like flatness, straightness, and perpendicularity. ISO 2768-1: Linear Dimensions (Class m)
The designation is an international standard used to define general tolerances for parts manufactured by material removal (such as CNC machining). It streamlines engineering drawings by providing a default "medium" precision level, eliminating the need to specify tolerances for every single dimension. Breaking Down the "mK" Designation