Specifications
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175/ISO 15156-2
- NORSOK M-650
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
Durehete 1055 vs 24CrMoV5-5 — EN 10269 Cr-Mo-V Bolting Steel Comparison
Durehete 1055 (Alloy T41 / 20CrMoVTiB4-10 / Werkstoff 1.7729) and 24CrMoV5-5 (Werkstoff 1.7733) are EN 10269 Cr-Mo-V bolting grades that overlap in service envelope but differ in carbon content and microalloying. 1055 carries the Ti+B addition; 24CrMoV5-5 is plain Cr-Mo-V at higher carbon.
Chemistry Comparison
| Element (wt %) | Durehete 1055 (20CrMoVTiB4-10) | 24CrMoV5-5 |
|---|---|---|
| Carbon | 0.17 to 0.23 | 0.20 to 0.28 |
| Silicon, max | 0.40 | 0.40 |
| Manganese | 0.35 to 0.75 | 0.40 to 0.70 |
| Chromium | 0.90 to 1.20 | 1.20 to 1.50 |
| Molybdenum | 0.90 to 1.10 | 0.45 to 0.60 |
| Vanadium | 0.60 to 0.80 | 0.25 to 0.35 |
| Titanium | 0.07 to 0.15 | not specified |
| Boron, max | 0.020 | not specified |
Mechanical Comparison (Q+T condition)
| Property | Durehete 1055 | 24CrMoV5-5 |
|---|---|---|
| Tensile strength, room temp | 820 to 1000 MPa | 800 to 950 MPa |
| 0.2% proof stress, min | 660 MPa | 620 MPa |
| Elongation, min | 16% | 15% |
Service Envelope
1055 covers 565°C continuous; 24CrMoV5-5 covers approximately 530-540°C. The 25-35°C gap is driven primarily by the Ti+B microalloying advantage on long-duration creep performance.
When to Specify Each Grade
Specify Durehete 1055 for upper-envelope HP turbine bolting and supercritical service. Specify 24CrMoV5-5 for service to 530°C where the higher carbon content delivers slightly higher hardness in compact bolt geometries and the cost premium of Ti+B microalloying isn't justified.
Frequently Asked Questions
What's the main difference between Durehete 1055 and 24CrMoV5-5?
Durehete 1055 has Ti+B microalloying; 24CrMoV5-5 doesn't. Above 530°C continuous service, the Ti+B advantage matters; below it, the grades are interchangeable.
Is 24CrMoV5-5 a stocked grade?
Yes — TorqBolt holds 24CrMoV5-5 bar in common bolting diameters alongside the Durehete grades. Lead time on custom diameters is comparable across the EN 10269 Cr-Mo-V family.
Does 24CrMoV5-5 have an ASTM equivalent?
Closest is ASTM A193 B16 territory but the chemistry windows do not align exactly. Dual certification requires negotiating the heat-treatment target with the mill.
Satisfaction Survey
