21CrMoV5-7 vs AFNOR 20CDV5.7

21CrMoV5-7 (Werkstoff 1.7709) and AFNOR 20CDV5.7 are the same Cr-Mo-V quenched-and-tempered bolting steel under different national designations. 21CrMoV5-7 is the EN 10269 / German designation; 20CDV5.7 is the French designation per NF A35-559. The chemistry windows and mechanical-property floors are essentially identical. French OEMs (EDF, Areva, Framatome, Alstom Power, Naval Group) typically call out 20CDV5.7 by name on procurement. TorqBolt supplies against either designation with EN 10204 certification documenting both cross-references.

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AFNOR designation decoded

The AFNOR code 20CDV5.7 reads:

• 20 = approximately 0.20 percent carbon
• C = chromium
• D = molybdenum (D in French rather than M, to avoid clash with manganese)
• V = vanadium
• 5.7 = the chromium and molybdenum target numerators (Cr at 5/4 = 1.25 percent, Mo at 7/10 = 0.7 percent, both within the EN 10269 windows for 21CrMoV5-7)

Equivalence statement

21CrMoV5-7 to EN 10269 = AFNOR 20CDV5.7 to NF A35-559 = Polish PN 21HMF to PN-89/H-84030. All three designations refer to the same Cr-Mo-V Q+T bolting steel chemistry. Cross-procurement projects ship under any of the three designations with single-heat compliance certified to the matching national standard.

When to specify 20CDV5.7

• French OEM equipment (EDF, Areva, Framatome, Alstom Power, Naval Group).
• Procurement framework is NF A35-559 rather than EN 10269.
• Legacy French-language drawings, specifications, and bills of material that pre-date EN harmonisation.
• Marine and naval bolting where French defence procurement specifies AFNOR designations.

Related cross-references

• vs Polish PN 21HMF — the Polish equivalent designation
• vs ASTM A193 B16 — closest US Cr-Mo-V analogue
• EN 10269 equivalents master table
• 21CrMoV5-7 chemistry

FAQs

Q. Are 21CrMoV5-7 and 20CDV5.7 truly identical?
Functionally yes. The chemistry windows and mechanical-property floors are essentially identical because the two designations describe the same Cr-Mo-V Q+T bolting steel under different national standards. A single melt can be certified to both without recipe change.

Q. Can a heat be dual-certified to both EN 10269 and NF A35-559?
Yes. The chemistry and mechanical-property floors overlap fully. EN 10204 type 3.1 or 3.2 certification can name both the EN 10269 21CrMoV5-7 and AFNOR 20CDV5.7 designations from a single heat lot.

Q. Which French OEMs procure to 20CDV5.7?
EDF (nuclear and conventional power), Areva (nuclear steam supply), Framatome (reactor pressure vessel and primary loop), Alstom Power (steam turbine), and Naval Group (marine bolting) typically call out 20CDV5.7 by name on French-language procurement documents.

Q. Can TorqBolt ship to 20CDV5.7 spec?
Yes. Stud bolts M12 to M120, hex bolts to M64, heavy hex to ASME B18.2.6, and matching nuts and washers under either designation with EN 10204 type 3.1 or 3.2 certification.