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
21CrMoV5-7 vs 42CrMo4 / AISI 4140
21CrMoV5-7 (Werkstoff 1.7709) and 42CrMo4 (Werkstoff 1.7225, AISI 4140 equivalent) are both quenched-and-tempered low-alloy steels but sit in different service classes. 21CrMoV5-7 is a Cr-Mo-V steel specified by EN 10269 for elevated-temperature bolting service to 550 deg C. 42CrMo4 is a general-purpose Cr-Mo (no vanadium) Q+T steel specified in EN 10083-3 for room-temperature mechanical-property requirements (shafts, gears, structural fasteners). The absence of vanadium caps 42CrMo4 at about 400 deg C continuous service. The two are not substitutes for each other; the selection driver is service temperature.
Chemistry contrast
| Element (wt%) | 21CrMoV5-7 (EN 10269) | 42CrMo4 (EN 10083-3 / 1.7225) |
|---|---|---|
| Carbon (C) | 0.17 to 0.25 | 0.38 to 0.45 |
| Silicon (Si) | max 0.40 | max 0.40 |
| Manganese (Mn) | 0.40 to 0.80 | 0.60 to 0.90 |
| Phosphorus (P) | max 0.025 | max 0.025 |
| Sulfur (S) | max 0.030 | max 0.035 |
| Chromium (Cr) | 1.20 to 1.50 | 0.90 to 1.20 |
| Molybdenum (Mo) | 0.55 to 0.80 | 0.15 to 0.30 |
| Vanadium (V) | 0.20 to 0.35 | not specified |
The defining differences: 42CrMo4 has roughly twice the carbon (0.38-0.45 vs 0.17-0.25), lower chromium, much lower molybdenum, and no vanadium. The result is higher static strength but no precipitation-strengthening at temperature.
Mechanical property floor
| Property | 21CrMoV5-7 (+QT, d ≤ 160 mm) | 42CrMo4 (+QT, d ≤ 60 mm) |
|---|---|---|
| 0.2 percent proof stress, min | 550 MPa | 730 MPa |
| Tensile strength | 700 to 850 MPa | 860 to 1060 MPa |
| Elongation A5, min | 16 percent | 14 percent |
| Reduction of area, min | 60 percent | 50 percent |
| Charpy V impact at +20 deg C, min | 63 J | 50 J |
42CrMo4 reaches higher static strength at room temperature than 21CrMoV5-7, but loses that strength rapidly above 400 deg C as carbides coarsen during long-term service. 21CrMoV5-7's V4C3 precipitates resist coarsening, holding strength to 550 deg C.
When to specify 21CrMoV5-7
- Elevated-temperature bolting service (450-550 deg C) where 42CrMo4 cannot serve.
- EN 10269 procurement framework; PED pressure vessels; VdTUV Wb 350 approved scope.
- Long-life creep performance is contractual; Charpy floor at +20 deg C explicitly required.
- Turbine casing flange bolting, steam piping, refinery elevated-temperature flange service.
When to specify 42CrMo4
- Room-temperature or sub-400 deg C service; structural bolting; machine elements.
- Higher static strength requirement at room temperature than 21CrMoV5-7 delivers.
- Shafts, gears, axles, anchor bolts, foundation bolts; general engineering hardware.
- EN 10083-3 procurement framework rather than EN 10269.
Related cross-references
- vs ASTM A193 B7 — US Cr-Mo without V, similar role to 42CrMo4 in elevated-temperature
- vs ASTM A193 B16 — closest US Cr-Mo-V analogue
- 21CrMoV5-7 chemistry
- 21CrMoV5-7 mechanical properties
FAQs
Q. Can 42CrMo4 substitute for 21CrMoV5-7 at elevated temperature?
No. Above 400 deg C continuous service, 42CrMo4 softens rapidly because it has no vanadium to form V4C3 precipitates that resist coarsening. For 450-550 deg C bolting service, 21CrMoV5-7 or B16 are the appropriate Cr-Mo-V grades.
Q. Is 42CrMo4 the same as AISI 4140?
Functionally equivalent for most applications. 42CrMo4 (1.7225) is the European EN 10083-3 designation; AISI 4140 is the closely matching American chemistry. There are small differences in S and Mn windows, and AISI 4140H specifies hardenability bands not in 42CrMo4. For most bolting and shafting applications either grade serves.
Q. Which is stronger at room temperature?
42CrMo4 reaches 860 to 1060 MPa tensile against 21CrMoV5-7's 700 to 850 MPa. 42CrMo4 wins on room-temperature strength. The win reverses above 400 deg C as 42CrMo4 softens and 21CrMoV5-7's V-strengthening kicks in.
Q. Can TorqBolt supply both?
Yes. Both grades are supplied as stud bolts, hex bolts, anchor bolts, threaded rod, nuts and washers with EN 10204 type 3.1 or 3.2 certification against the relevant standard (EN 10269 for 21CrMoV5-7; EN 10083-3 for 42CrMo4).
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