| Nominal Size Range (mm) | Tolerance (mm) | |------------------------|----------------| | ≤ 100 | 0.2 | | >100 to 300 | 0.3 | | >300 to 1000 | 0.4 | | >1000 to 3000 | 0.5 |

| Shorter Side Length (mm) | Tolerance | | :--- | :--- | | Up to 10 | ±1° | | Over 10 up to 50 | ±0°30′ | | Over 50 up to 120 | ±0°20′ | | Over 120 up to 400 | ±0°10′ | | Over 400 | ±0°5′ |

To understand the "mh" combination, one must first understand the parent standard, ISO 2768. It is divided into two parts:

What you are using (CNC machining, sheet metal, injection molding)? What materials your parts are made of? Do you have mating parts that require specific fits? Share public link

The Ultimate Guide to the ISO 2768-mH Tolerance Chart The standard is a globally recognized blueprint for manufacturing and design that dictates general dimensional and geometrical tolerances for machined parts without individual tolerance indications. The "mH" designation is a combination of two specifications: m for medium linear tolerance (ISO 2768-1) and H for H-class geometrical tolerance (ISO 2768-2).

While it is an excellent general baseline, ISO 2768-mh is not a magic bullet. You should override these general tolerances with specific, tighter dimensions in the following scenarios:

Example 1 — Shaft diameter called Ø25 mm on a drawing with "ISO 2768‑m" specified.

Best practices:

Symmetry controls the central positioning of features, while run-out limits errors in rotating elements.