Iso 2768-mh Tolerance Chart Best -

If you are a quality engineer receiving parts with this note, follow these guidelines:

A 5mm chamfer callout with no tolerance is allowed to be 4.5mm to 5.5mm. That is a massive 20% variation. If you need a cosmetic 45° x 1.5mm chamfer, you must explicitly tolerance it as max 1.6mm/ min 1.4mm. iso 2768-mh tolerance chart

This international standard simplifies technical drawings by providing "general tolerances." If a specific tolerance isn't noted next to a dimension, the workshop refers to this chart to understand the allowable margin of error. If you are a quality engineer receiving parts

Next time you see that title block, you’ll know exactly what margin of error the shop floor is working with. Straightness and Flatness Range of Nominal Length (mm)

The "H" class defines strict limits for form and position, such as how straight or perpendicular a feature must be. Straightness and Flatness Range of Nominal Length (mm) Tolerance (mm) Over 10 to 30 Over 30 to 100 Over 100 to 300 Over 300 to 1,000 Over 1,000 to 3,000

If a feature is critical for a "press-fit" (like a bearing housing) or requires extreme precision for airtight seals, . In those specific cases, you must manually define a tighter tolerance (e.g., +/- 0.01mm) directly on that dimension.