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EN 10269 — Steels & Nickel Alloys for Fasteners with Specified Elevated and/or Low Temperature Properties
EN 10269 is the European standard for bolting and fastener materials with specified elevated-temperature or low-temperature properties. The current revision is EN 10269:2014+A1:2024. The standard covers carbon, Cr-Mo, Cr-Mo-V, Cr-Mo-V-Ti-B, austenitic stainless and nickel-base alloys grouped into 35 grade designations. Durehete 1055, 950 and 900 are the trade names for three of the EN 10269 Cr-Mo-V family grades: 20CrMoVTiB4-10 (1.7729), 40CrMoV4-6 (1.7711) and 42CrMoV5-6 respectively.
Scope
EN 10269 specifies the technical delivery conditions for bars, wire rod, semi-finished products, forgings and finished fasteners (bolts, screws, studs, nuts, washers) intended for service at elevated temperature, low temperature, or both. The standard governs chemistry ranges, heat-treatment condition, mechanical-property requirements (room temperature plus elevated-temperature 0.2 percent proof stress and 100,000-hour stress-rupture in Annex A), inspection categories to EN 10204, and marking.
Grade Matrix
| Family | Example grades | Service envelope | Common application |
|---|---|---|---|
| Carbon and C-Mn | C35E, C45E, 25CrMo4 | up to 350°C | General pressure-vessel bolting |
| Cr-Mo | 21CrMoV5-7, 25CrMo4 | up to 480°C | Petrochemical fired heater |
| Cr-Mo-V | 40CrMoV4-6 (Durehete 950), 42CrMoV5-6 (Durehete 900) | up to 540°C | IP / LP turbine flange bolting |
| Cr-Mo-V-Ti-B | 20CrMoVTiB4-10 (Durehete 1055) | up to 565°C | HP / supercritical turbine bolting |
| Austenitic stainless | X6CrNiMoB17-12-2, X10CrNiMoNb18-12 | up to 700°C | Sour service + cryogenic |
| Nickel-base | NiCr20TiAl, NiCr19Fe19Nb5Mo3 | up to 750°C | Gas turbine, ultra-supercritical |
ASTM Cross-References
| EN 10269 grade | Closest ASTM A193 / A194 / A540 equivalent |
|---|---|
| 20CrMoVTiB4-10 (Durehete 1055 / T41) | No exact ASTM equivalent — closest is ASTM A540 B23 / B24 family but Ti+B microalloying is unique to the EN family |
| 40CrMoV4-6 (Durehete 950 / T31) | ASTM A193 Grade B16 |
| 42CrMoV5-6 (Durehete 900 / T22) | ASTM A193 Grade B16 (lower-temperature service) |
| 21CrMoV5-7 | ASTM A193 Grade B16 |
| X6CrNiMoB17-12-2 | ASTM A193 Grade B8M / A194 Grade 8M |
Annex A — Elevated-Temperature Design Data
Annex A of EN 10269 publishes 0.2 percent proof stress at elevated temperature and 100,000-hour stress-rupture values for every grade. These are the lookup tables that drive bolted-joint design at high temperature. Annex B carries stress-relaxation curves for re-tightening interval calculations.
Inspection & Marking
EN 10204 inspection certificates are mandatory: type 3.1 by default, type 3.2 when a notified body or third-party witness is required. Marking on the bolt head includes the grade designation plus the manufacturer identifier and traceability code.
Frequently Asked Questions
What is EN 10269?
The European standard for steels and nickel alloys used in fasteners and bolting with specified elevated or low temperature properties. Current revision is EN 10269:2014+A1:2024.
Where does Durehete 1055 sit in the EN 10269 grade matrix?
Durehete 1055 is the trade name for 20CrMoVTiB4-10 (Werkstoff 1.7729), the highest-temperature member of the Cr-Mo-V-Ti-B family in the standard. Service envelope reaches 565°C continuous.
What is the closest ASTM equivalent to EN 10269 grade 20CrMoVTiB4-10?
There is no exact ASTM equivalent. The closest ASTM bolting standards are A540 B23 / B24 but the titanium and boron microalloying is unique to the European Cr-Mo-V-Ti-B family. ASTM A193 B16 is the equivalent for EN 10269 40CrMoV4-6 (Durehete 950).
Where can I download EN 10269?
EN 10269 is published by CEN and sold through national standards bodies (BSI, DIN, AFNOR, ASI). The standard is not available as a free PDF; purchase via your national standards body or ISO Store.
Does EN 10269 cover stress-relaxation data?
Yes. Annex B publishes residual-stress curves at 1,000, 10,000 and 30,000 hours for each elevated-temperature grade.
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