The precision level of a welded part is defined by four tolerance classes:
is considered "medium" or standard workshop accuracy. Class D is the coarsest (largest tolerances).
This article explores the DIN 8570-1 standard, specifically focusing on Tolerance Class B, its application, and how to acquire the relevant documentation. What is DIN 8570-1? din 8570 b pdf
| Imperfection | Quality Level B Limit | |--------------|------------------------| | Longitudinal crack | Not permitted | | Transverse crack | Not permitted | | Porosity (single pore) | Max. 0.3 mm diameter | | Porosity (cluster) | Max. 2% of weld area | | Undercut | Depth ≤ 0.5 mm | | Excess weld metal (reinforcement) | ≤ 1 mm + 0.1 x weld width | | Incomplete penetration | Not permitted (except by design) | | Concavity (root side) | ≤ 0.5 mm | | Linear misalignment | ≤ 0.2 x plate thickness, max. 2 mm |
Since DIN 8570 directly maps to ISO 13920, purchasing the ISO 13920 PDF provides the globally recognized equivalent. The precision level of a welded part is
The hunt for a is a symptom of a deeper engineering challenge: managing long-lived assets against evolving standards. While the document itself is obsolete, its requirements still govern thousands of active contracts.
Because DIN standards are copyrighted, official PDF copies must be purchased through authorized distributors like Beuth Verlag or ISO-affiliated stores. Using official versions ensures you are working with the most recent updates and avoids the errors often found in unofficial "summary" sheets found online. What is DIN 8570-1
Very coarse tolerances. Used for rough structures where alignment is achieved through secondary operations or substantial clearance.
If your document says “DIN 8570 B” specifying “Part 1” or “Part 2,” assume Part 2, Quality Level B (weld imperfections).
Instead of specifying a tolerance for every single dimension, designers can reference DIN 8570-1, allowing the workshop to work within a recognized, customary range of accuracy. Understanding DIN 8570 Tolerance Classes