B | Din 8570

For linear measurements—such as external dimensions, internal distances, or center-line offsets—the following approximate limit deviations for Class B apply: Nominal Dimension Range (mm) Tolerance for Class B (± mm) Over 30 to 120 Over 120 to 400 Over 400 to 1000 Over 1000 to 2000 Over 2000 to 4000 2. Angular Dimensions

In 1996, DIN 8570 was officially replaced by DIN EN ISO 13920 . Modern projects should typically reference the ISO equivalent, though the tolerance values in ISO 13920 Class B are functionally similar to those in the original DIN standard. Implementation in Engineering General Tolerances for Welded Structures | PDF - Scribd

Many drawings specify a root face (e.g., 1.5 mm) but do not cite DIN 8570 B. Without the standard, you have no allowable deviation. With the standard, a Class 3 tolerance might allow ±0.5 mm. din 8570 b

Specifically, DIN 8570 B defines .

Detailed technical tables and comparisons with other classes can be found on resources like Scribd's DIN 8570 Guide Intertek Inform database table of specific tolerance values for different length ranges under Class B? Din 8570-1987 | PDF | Engineering Tolerance - Scribd Specifically, DIN 8570 B defines

Using Class A when you don't need it drives up costs. DIN 8570 Class B (or ISO 13920 Class B) is the "workhorse" of the industry. It provides enough precision for structural integrity without requiring microscopic adjustments that slow down production.

Flame cutting typically yields Class 3 or 4 due to the naturally rough surface (kerf drag lines). Machining is required to achieve Class 1 or 2. For linear measurements—such as external dimensions

The defining characteristic of the "B" type is the projection length ($L$). This is the distance from the back of the taper shank to the front of the chuck jaws.