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 ASTM A193 Grade B16
21CrMoV5-7 (Werkstoff 1.7709) and ASTM A193 Grade B16 are both Cr-Mo-V quenched-and-tempered bolting steels for elevated-temperature service to about 540 to 550 deg C. They are not chemistry-identical. B16 carries roughly twice the carbon and lower chromium than 21CrMoV5-7. The result: B16 reaches higher strength in small sections; 21CrMoV5-7 trades peak strength for deeper hardenability and tighter Cr stability for long-life creep service. European procurement (Siemens, MAN, Areva, BHEL, PED pressure vessels, VdTUV Wb 350) defaults to 21CrMoV5-7. US procurement (GE, Westinghouse, ASME BPVC Section VIII, ASME B31.3, API refinery flanges) defaults to B16. Most cross-procurement projects buy the locally-spec'd grade rather than dual-certify, because the chemistry windows do not overlap.
Chemistry side by side
| Element (wt%) | 21CrMoV5-7 (EN 10269) | ASTM A193 B16 |
|---|---|---|
| Carbon (C) | 0.17 to 0.25 | 0.36 to 0.47 |
| Silicon (Si) | max 0.40 | 0.15 to 0.35 |
| Manganese (Mn) | 0.40 to 0.80 | 0.45 to 0.70 |
| Phosphorus (P) | max 0.025 | max 0.035 |
| Sulfur (S) | max 0.030 | max 0.040 |
| Chromium (Cr) | 1.20 to 1.50 | 0.80 to 1.15 |
| Molybdenum (Mo) | 0.55 to 0.80 | 0.50 to 0.65 |
| Vanadium (V) | 0.20 to 0.35 | 0.25 to 0.35 |
| Nickel (Ni) | max 0.60 | not specified |
| Boron (B) | not specified | max 0.015 |
Carbon and chromium ranges do not overlap. A heat that passes 21CrMoV5-7 will fail B16 on low carbon; a heat that passes B16 will fail 21CrMoV5-7 on low chromium.
Mechanical property floor
| Property | 21CrMoV5-7 (+QT, d ≤ 160 mm) | ASTM A193 B16 (M64 / 2.5 in. and under) |
|---|---|---|
| 0.2 percent proof stress, min | 550 MPa | 725 MPa |
| Tensile strength | 700 to 850 MPa | min 860 MPa |
| Elongation A5, min | 16 percent | 18 percent |
| Reduction of area, min | 60 percent | 50 percent |
| Charpy V impact at +20 deg C, min | 63 J | not specified at +20 deg C |
| Hardness ceiling | via tensile cap | 321 HBW or 35 HRC |
B16 sits a tier above 21CrMoV5-7 on strength but EN 10269 imposes a Charpy floor (63 J at room temperature) and a tighter tensile ceiling, which B16 does not. For toughness-driven service, the EN 10269 floor is the harder envelope to clear.
Heat treatment
- 21CrMoV5-7: austenitise 880 to 940 deg C, oil quench, temper 680 to 740 deg C. See heat treatment.
- ASTM A193 B16: austenitise 925 to 955 deg C, oil quench, temper per A193 Tables 2 and 3 (minimum tempering temperature is specified).
When to specify 21CrMoV5-7
- Procurement framework is European: Siemens, MAN, Areva, BHEL turbine bolting; PED pressure vessels; VdTUV Wb 350 approved scope.
- Service requires the EN 10269 Charpy floor (63 J at +20 deg C) explicitly documented.
- Large-section forgings up to 160 mm where deeper hardenability and tighter Cr stability matter for long-life creep performance.
- End-user maintains a 21CrMoV5-7 inventory and wants a single-grade fleet across multiple plants.
When to specify ASTM A193 Grade B16
- Procurement framework is US: ASME BPVC Section VIII pressure vessels; ASME B31.3 piping; API refinery flange standards; GE or Westinghouse OEM design.
- Higher static strength requirement (1200 MPa class tensile under 65 mm, 860 MPa class above) within the same Cr-Mo-V envelope.
- S12 supplement (B16R) called out for elevated-temperature stress rupture testing per A193 Annex.
- Project ships with EN 10204 type 3.1 / 3.2 against the A193 standard rather than EN 10269.
Dual certification
Because the carbon and chromium ranges do not overlap, dual certification to both EN 10269 21CrMoV5-7 and ASTM A193 B16 from a single heat is rare. Where a project genuinely needs both, the practical route is: melt to the tighter standard (usually 21CrMoV5-7 because of the lower carbon ceiling), then certify against the European spec only and cross-reference B16 by procurement equivalence. TorqBolt ships EN 10204 type 3.1 by default, type 3.2 with Lloyd's, DNV, BV, SGS or TUV witness on call-out.
Related cross-references
- vs ASTM A193 B7 — Cr-Mo without vanadium, 450 deg C envelope
- vs ASTM A193 B8 — austenitic stainless, different alloy class
- vs 21CrMoV5-11 — heavier-section sister grade in EN 10269
- vs Durehete 1055 — premium Ti+B microalloyed step-up
- EN 10269 equivalents master table
FAQs
Q. Are 21CrMoV5-7 and ASTM A193 B16 the same steel?
No. They sit in the same Cr-Mo-V quenched-and-tempered class for elevated-temperature bolting, but B16 carries 0.36 to 0.47 percent carbon against 21CrMoV5-7 at 0.17 to 0.25, and 0.80 to 1.15 percent chromium against 1.20 to 1.50. The ranges do not overlap.
Q. Which is stronger?
B16 in small sections (under 65 mm) reaches a 1200 MPa class tensile against 21CrMoV5-7 at 700 to 850 MPa. Above 65 mm B16 drops to a min 860 MPa class. The strength gap closes in the heavy-section range where 21CrMoV5-7 deeper hardenability narrows the difference.
Q. Which is tougher?
EN 10269 specifies a 63 J minimum Charpy V at +20 deg C for 21CrMoV5-7. A193 B16 does not specify an impact floor at room temperature. For toughness-driven service the EN 10269 floor is the harder requirement to clear.
Q. Can a single heat satisfy both standards?
Rarely. Carbon and chromium ranges do not overlap, so dual chemistry compliance requires the steelmaker to hit narrow simultaneous windows that do not exist in the published ranges. Cross-procurement projects ship the locally-spec'd grade.
Q. What is the closest US equivalent to 21CrMoV5-7?
B16 is the canonical cross-reference because both are Cr-Mo-V Q+T grades for the same service envelope, but they are not interchangeable on chemistry. There is no exact US equivalent. ASTM A540 Grade B22 and B23 are sometimes considered for the higher-strength step.
Q. Can TorqBolt supply both grades?
Yes. Stud bolts M12 to M120, hex bolts to M64, heavy hex bolts to ASME B18.2.6, and matching nuts and washers are supplied in either grade with EN 10204 type 3.1 or 3.2 certification. Request a quote with the project standard, size range and quantity.
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