Tolerance Iso 2768 Mk Pdf [RECOMMENDED]
Angular tolerances are determined by the length of the shorter side of the angle.
| Length of the shorter side (mm) | Tolerance (degrees/minutes) | | :--- | :--- | | Up to 10 | $\pm 1^\circ$ | | Over 10 up to 50 | $\pm 0^\circ 30'$ | | Over 50 up to 120 | $\pm 0^\circ 20'$ | | Over 120 up to 400 | $\pm 0^\circ 10'$ | | Over 400 | $\pm 0^\circ 5'$ |
For angles (e.g., a 45° chamfer), the "m" class allows a tolerance of ± 1° for nominal lengths shorter than 120 mm, and ± 0.5° for longer lengths.
The Tolerance ISO 2768 MK PDF is more than just a file download; it is a bridge between design intent and manufactured reality. By specifying "m" for linear dimensions and "K" for geometry, the engineer communicates a standard level of precision suitable for most turned, milled, and drilled components.
To ensure success on your next project:
For 80% of mechanical components, the medium precision of ISO 2768 MK is the perfect balance between manufacturing cost and quality. Get your reference chart today, and never guess a tolerance again. Tolerance Iso 2768 Mk Pdf
Disclaimer: This article is for informational purposes. Tolerance values are summarized for clarity. For legal manufacturing contracts, always refer to the official ISO 2768:1989 or ISO 2768-1:1989 and ISO 2768-2:1989 standards as updated by your regional standards body.
Understanding ISO 2768-mk: The Standard for General Geometrical Tolerances
ISO 2768-mk is an international quality standard designed to simplify technical drawings by providing general tolerances for linear and angular dimensions, as well as geometrical specifications (such as flatness and symmetry). It is the backbone of efficient manufacturing, ensuring that parts fit together correctly without requiring every single dimension to be individually toleranced. The Purpose of ISO 2768
In engineering design, specifying tolerances for every dimension is time-consuming and often leads to cluttered drawings. ISO 2768 solves this by establishing a "default" level of precision. When a designer specifies ISO 2768-mk on a drawing, they are instructing the manufacturer to follow a specific set of accuracy rules for any dimension that doesn't have its own unique tolerance. Breaking Down the "mk" Designation The designation is split into two distinct parts:
"m" (General Tolerances for Linear and Angular Dimensions): This letter refers to Part 1 of the standard. The "m" stands for Medium. Other classes include 'f' (fine), 'c' (coarse), and 'v' (very coarse). Angular tolerances are determined by the length of
"k" (General Geometrical Tolerances): This letter refers to Part 2 of the standard, which covers features like straightness, flatness, and circularity. The "k" represents a specific tolerance class for these geometric characteristics. Other classes in Part 2 include 'H' and 'L'. Key Components of the Standard
Linear Dimensions: These cover the permissible deviation in length, such as external sizes, internal sizes, and step sizes. The tolerance increases as the size of the part increases.
Angular Dimensions: These define the allowed error in degrees and minutes for angles, also scaled based on the length of the shorter leg of the angle.
Geometrical Tolerances: This includes limits on how much a surface can warp (flatness) or how much two features can be off-center (symmetry/run-out). Why ISO 2768-mk is the Industry Favorite
The "mk" combination is widely considered the industry standard for general machining. It provides a balance that is precise enough for most mechanical assemblies while remaining achievable for standard CNC machines and manual tools without driving up production costs. For angles (e
By using this standard, companies reduce the time spent on "dimensioning and tolerancing" (GD&T), minimize disputes between designers and machinists, and ensure a baseline level of quality across global supply chains.
The tolerance values depend on the length of the feature.
| Nominal Length (mm) | Tolerance (Class K) | | :--- | :--- | | Up to 10 | 0.05 mm | | Over 10 up to 30 | 0.10 mm | | Over 30 up to 100 | 0.15 mm | | Over 100 up to 300 | 0.20 mm | | Over 300 up to 1000 | 0.30 mm |
The magic is in the suffix: m and K.
Searching for a free "ISO 2768 MK PDF" is dangerous. Many "free" versions online are:
Where to get the legitimate PDF:
