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Durehete 950 (EN 10269 / Alloy T31 / Werkstoff 1.7711 / 40CrMoV4-6 / ASTM A193 B16) Cr-Mo-V High-Temperature Bolting Steel
Durehete 950 is the middle grade of the Durehete family of Cr-Mo-V creep-resistant bolting steels. The grade has a fully documented cross-reference chain: Durehete 950 = Alloy T31 = Werkstoff 1.7711 = EN designation 40CrMoV4-6, with a documented US bolting equivalent of ASTM A193 B16 Annex A. The primary controlling specification is EN 10269. The 950 in the trade name encodes the maximum design temperature of approximately 950°F. The producer of the bar pedigree is Tata Steel UK (formerly Corus Products USA).
Durehete 950 is supplied by TorqBolt as custom-machined high-temperature bolts, stud bolts, hex bolts, heavy hex bolts, tap studs, weld studs, body-bound studs, couplings, U-bolts, fasteners, round bar and forging stock. Procurement is by EN 10269 specification call-out for European and UK power-generation, process-plant and turbine-fastener applications. The documented US bolting alias ASTM A193 B16 is provided for buyers procuring under an ASTM-anchored specification.
Durehete 950 Characteristics and Key Properties
Durehete 950 / Alloy T31 is the middle grade of the Durehete creep-resistant bolting family. Its EN designation under EN 10269 is 40CrMoV4-6 and its Werkstoff number is 1.7711. EN 10269 Annex A documents ASTM A193 B16 as the US bolting equivalent. The grade sits one step below Durehete 1055 / Alloy T41 / 1.7729 / 20CrMoVTiB4-10 and one step above Durehete 900 / Alloy T22 / 42CrMoV5-6 on the family service-temperature ladder.
Durehete 950 Chemical Composition (EN 10269 / 40CrMoV4-6 / Werkstoff 1.7711)
Durehete 950 is procured to the EN 10269 designation 40CrMoV4-6 (Werkstoff 1.7711). The corresponding US bolting alias under EN 10269 Annex A is ASTM A193 B16. Buyers should reference EN 10269 Annex A and the EN 10269 Annex A sheet for full element ranges; the values below summarise the grade and are not a substitute for the EN 10269 / ASM specification itself.
| Designation | Body | Notes |
|---|---|---|
| Durehete 950 | Trade name | Family middle grade |
| Alloy T31 | Trade alias | Per producer datasheets |
| 40CrMoV4-6 | EN 10269 designation | Primary specification |
| 1.7711 | Werkstoff number | To EN 10269 |
| ASTM A193 B16 | US bolting alias | To EN 10269 Annex A |
Durehete 950 Mechanical Properties (Quenched and Tempered)
Mechanical envelope for Durehete 950 / Alloy T31 is governed by EN 10269 for the European specification route and by ASTM A193 B16 (per ASM SA-145) for the US bolting route. Detail on the mechanical properties page.
Durehete 950 Heat Treatment
Durehete 950 is supplied in the quenched-and-tempered condition. The tempering temperature is selected by the mill to balance yield strength and creep-rupture life for the specific bar diameter and the EN 10269 inquiry under which the heat is produced.
Durehete 950 Welding Notes
Bolting in Durehete 950 is supplied in the quenched-and-tempered condition and is not field-welded. Where repair-weld qualifications are required, procedure development should follow the producer datasheet and the project EN 10269 Annex A inquiry. Refer to the welding page for procedure-development notes.
Durehete 950 Standards Cross-Reference (EN 10269 Anchored)
Durehete 950 is the only grade in the Durehete family with a published US bolting equivalent in EN 10269 Annex A. The cross-reference chain is documented below.
| Designation | Body | Notes |
|---|---|---|
| EN 10269 | European harmonised | Primary specification |
| 40CrMoV4-6 | EN 10269 | EN designation for Durehete 950 |
| 1.7711 | Werkstoff | Werkstoff number |
| Alloy T31 | Trade alias | Per producer datasheets |
| ASTM A193 B16 | ASTM | Documented US bolting equivalent Annex A |
Durehete 950 Applications (per Producer Datasheets)
Applications for Durehete 950 / Alloy T31 follow the same envelope as the rest of the Durehete family at the middle service-temperature step:
- Turbine fasteners for European and UK power-generation OEMs and EPC contractors
- Boiler support rods and fasteners at elevated service temperature
- Power generation bolting under EN 10269 inquiry
- General process plant elevated-temperature bolted joints
Durehete 950 vs Durehete 1055 vs Durehete 900
EN 10269 is the primary specification for all three Durehete grades. Within the family they are graded by maximum design temperature, encoded in the °F number that gives each grade its name.
| Grade | EN designation | Werkstoff | Trade alias | US alias (where documented) |
|---|---|---|---|---|
| Durehete 1055 | 20CrMoVTiB4-10 | 1.7729 | Alloy T41 / T41 | n/a |
| Durehete 950 | 40CrMoV4-6 | 1.7711 | Alloy T31 | ASTM A193 B16 (ASM SA-145) |
| Durehete 900 | 42CrMoV5-6 | Alloy T22 | n/a |
Durehete 950 Forms and Fasteners
Durehete 950 is a bolting steel. TorqBolt supplies it as custom-machined bolts and stud bolts produced from forged bar stock through the full Q+T cycle to EN 10269. Mill test certificate (EN 10204 type 3.1 by default, type 3.2 on request) is available cross-referenced to ASTM A193 B16 where the project specifies under the US route.
| Form Category | Products |
|---|---|
| Bar and forging stock | Round bar to EN 10269 / ASTM A193 B16, forging stock for in-house bolt-making |
| High-temperature bolting | Bolts, hex bolts, heavy hex bolts, stud bolts, tap studs, weld studs, body-bound studs |
| Specialised fasteners | Couplings, U-bolts, threaded rod, nuts, washers, anchor bolts |
Durehete 950 Frequently Asked Questions
What is Durehete 950?
Durehete 950 is a Cr-Mo-V creep-resistant alloy steel for high-temperature bolting under EN 10269. It is also known as Alloy T31, Werkstoff 1.7711, and EN designation 40CrMoV4-6. EN 10269 Annex A documents ASTM A193 B16 as its US bolting equivalent.
What is the EN designation for Durehete 950?
40CrMoV4-6. The Werkstoff number is 1.7711.
What is the documented US bolting equivalent of Durehete 950?
ASTM A193 B16 Annex A.
What is the heat treatment for Durehete 950?
Quenched and tempered. The tempering temperature is selected by the mill to balance yield strength and creep-rupture life. Full detail on the heat treatment page.
What MTC do you supply with Durehete 950 bolting?
EN 10204 type 3.1 by default and type 3.2 on request. Heat number, full chemistry cross-referenced to EN 10269 (40CrMoV4-6) and ASTM A193 B16, mechanical test results, full Q+T heat-treatment chart and dimensional report tied to the heat lot. Third-party witness inspection (LR, DNV, BV, SGS, TUV) is available on call-out.
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