Welding – General tolerances for welded constructions – Dimensions for lengths and angles, shape and position

ISO 13920:2023 Welding Tolerances Calculator

General tolerances for welded constructions — Dimensions for lengths and angles, shape and position

1 Table 1 — Tolerances for Linear Dimensions

Nominal Size (l) in mm:

Tolerance Class: Select tolerance class Class A (Fine) Class B (Medium) Class C (Coarse) Class D (Very Coarse)

Calculate Linear Tolerance

Linear Tolerance Result

Nominal Size:

Tolerance Class:

Tolerance (t):

Acceptable Range:

2 Table 2 — Tolerances for Angular Dimensions

Examples showing how the shorter angle leg, l, is represented

Length of Shorter Leg (l) in mm:

Tolerance Class: Select tolerance class Class A (Fine) Class B (Medium) Class C (Coarse) Class D (Very Coarse)

Calculate Angular Tolerance

Angular Tolerance Result

Shorter Leg Length:

Tolerance Class:

Angular Tolerance (Δα):

Tolerance in mm/m:

Actual Tolerance (mm):

3 Table 3 — Straightness, Flatness and Parallelism Tolerances

Nominal Size (l) – Longer Side of Surface in mm:

Tolerance Class: Select tolerance class Class E (Fine) Class F (Medium) Class G (Coarse) Class H (Very Coarse)

Calculate Shape Tolerance

Shape Tolerance Result

Nominal Size:

Tolerance Class:

Tolerance (t):

4 6.2 — Straightness Test

Straightness test: h_max – h_min ≤ t

Testing Method: The edge of the weldment and the straightedge shall be aligned so that the greatest distance between them is at its minimum. Measure the distance between the edge and the straightedge.

Maximum Height (h_max) in mm:

Minimum Height (h_min) in mm:

Allowed Tolerance (t) in mm:

Check Straightness Compliance

Straightness Test Result

Measured Deviation:

Allowed Tolerance:

Compliance Status:

5 6.3 — Flatness Test

Flatness test: h_max – h_min ≤ t

Testing Method: The actual surface and measuring plane shall be aligned so that the greatest distance between them is at its minimum. Measure distances between the actual surface and the measuring plane.

Maximum Height (h_max) in mm:

Minimum Height (h_min) in mm:

Allowed Tolerance (t) in mm:

Check Flatness Compliance

Flatness Test Result

Measured Deviation:

Allowed Tolerance:

Compliance Status:

6 6.4 — Parallelism Test

Parallelism test: h_max – h_min ≤ t

Testing Method: Align the reference surface parallel to the reference plane. Establish a measuring plane parallel to the reference plane. Measure distances between the actual surface and the measuring plane.

Maximum Height (h_max) in mm:

Minimum Height (h_min) in mm:

Allowed Tolerance (t) in mm:

Check Parallelism Compliance

Parallelism Test Result

Measured Deviation:

Allowed Tolerance:

Compliance Status:

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Soudage — Tolérances générales relatives aux constructions soudées — Dimensions des longueurs et angles, formes et positions