Specification summary of DIN 791 as applied to standard (raised) expanded metal: what the standard controls, the tolerance system it defines, the full specification range, and the equivalent ISO/ASTM/DIN documents.
DIN 791 — Scope
DIN 791 specifies the designation system, dimensions and tolerances of standard (raised) expanded metal — mesh count or nominal opening, wire diameter and the permissible aperture deviations. Alloy chemistry, mechanical testing and delivery condition are governed by separate documents in the same standards family.
Tolerance Classes
DIN 791 defines tolerance limits on the average aperture and on the maximum single aperture, tightening as the aperture gets finer. For test-sieve duty the tighter ISO 3310-1 tolerances apply instead of the general cloth tolerances — specify sieve grade explicitly if the mesh will be used for particle-size analysis.
Specifications Defined by DIN 791
| Mesh designation (SWD x LWD) | SWD (mm) | LWD (mm) | Strand width (mm) | Strand thickness (mm) | Open area (%) |
|---|---|---|---|---|---|
| 6x12 | 6 | 12 | 1.0 | 1.0 | 62 |
| 10x20 | 10 | 20 | 1.5 | 1.5 | 66 |
| 12.5x25 | 12.5 | 25 | 2.0 | 2.0 | 60 |
| 16x34 | 16 | 34 | 2.0 | 2.0 | 70 |
| 22x50 | 22 | 50 | 3.0 | 3.0 | 67 |
| 30x60 | 30 | 60 | 3.5 | 3.0 | 72 |
| 50x100 | 50 | 100 | 5.0 | 4.0 | 75 |
Equivalent Standards
Where direct equivalents exist (ISO ↔ ASTM ↔ DIN), they are listed on the parent Standard (Raised) Expanded Metal page. Confirm against the specification table on this page — nominally equivalent documents can differ in tolerance limits.
When to Specify DIN 791
DIN 791 remains common in European engineering and on legacy drawings; for new international programs reference the ISO equivalent alongside it.