Steel 21CrMoV5-7
EN 21CrMoV5-7
21CrMoV5-7 (1.7709) is a quenched and tempered chromium-molybdenum-vanadium alloy steel in the EN 10083 family, specified for high-temperature, high-pressure components that need creep resistance together with toughness.
Reference datasheet — 21CrMoV5-7 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the +QT condition
21CrMoV5-7 tempers and conditions
21CrMoV5-7 is supplied in 5 conditions, soft to hard. +QT is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Lowest-hardness stock condition for rough machining or re-forging; requires subsequent Q&T for service. | 420 | 660 | 24 | 14 HRC | 7.5 % IACS |
Spheroidize annealed | Pick for bar or wire that must be cold headed, deep-drilled or heavily machined before the final quench-and-temper. | 450 | 700 | 22 | 215 HB | — |
Normalized | Grain-refining intermediate condition after forging, prior to quench and temper. | 560 | 820 | 17 | 24 HRC | 7.2 % IACS |
+QTDefault Quenched and tempered | Standard supply condition for high-temperature bolts, studs, valve stems and forgings up to ~550 °C service. | 700 | 830 | 18 | 25 HRC | — |
+QT high-strength | Choose for bolt diameters below ~100 mm where the higher Rp0.2 class (≥700 MPa) is specified. | 780 | 880 | 15 | 28 HRC | — |
What is 21CrMoV5-7?
21CrMoV5-7 (1.7709) is a quenched and tempered chromium-molybdenum-vanadium alloy steel in the EN 10083 family, specified for high-temperature, high-pressure components that need creep resistance together with toughness. In +QT it provides 700 MPa yield, 830 MPa tensile, 18% elongation and about 250 HB (25 HRC) with service to 540 °C; usual forms are bar, forged bolts and studs, and valve bodies. It welds only with preheat and PWHT and has no inherent corrosion resistance, so hot bolting needs anti-seize. 40CrMoV4-6 (1.7711) is the nearest higher-strength alternative where creep life matters less. 21CrMoV5-7 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,450°C (2,642 °F). 21CrMoV5-7 has a yield strength of 700 MPa (102 ksi) and a tensile strength of 830 MPa (120 ksi) — stronger than 81% of steel grades. Elongation at break is 18% and the elastic modulus is 210 GPa (30.5 Msi).
What is 21CrMoV5-7 used for?
- Steam turbine bolts and shafts
- High-pressure valve bodies
- Boiler and pipeline fittings
- Power plant fasteners
Advantages
- High service temperature — 540°C (1,004 °F), better than 93% of steel grades
- High strength — 700 MPa (102 ksi), better than 81% of steel grades
Limitations
- Limited formability — 22/100, worse than 76% of steel grades
21CrMoV5-7 properties
Typical room-temperature values for 21CrMoV5-7-+QT; bars are the position among steel grades.
Physical3
21CrMoV5-7 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,450°C (2,642 °F).
Mechanical16
21CrMoV5-7 has a yield strength of 700 MPa (102 ksi) and a tensile strength of 830 MPa (120 ksi) — stronger than 81% of steel grades. Elongation at break is 18% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
21CrMoV5-7 is rated for continuous service to 540°C (1,004 °F). It conducts heat at 39 W/m·K (22.5 BTU/hr·ft·°F), worse than 67% of steel grades. Thermal expansion is 12.2 µm/m·K (6.78 µin/in·°F).
Electrical3
21CrMoV5-7 conducts electricity at 7.2 % IACS, worse than 71% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 21CrMoV5-7 takes about 32 MJ of energy and emits 2.3 kg of CO₂ — more than 70% of steel grades. Typical recycled content is 25%.
Manufacturability7
21CrMoV5-7's machinability is fair (42/100, worse than 73% of steel grades); weldability fair (35/100); formability poor (22/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the steel family
Yield strength against density for every steel grade FabDigit runs. 21CrMoV5-7 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 21CrMoV5-7
Is 21CrMoV5-7 easy to machine?
Machine in +AC/+A condition where possible; in +QT (≈250 HB) use rigid setups, carbide inserts at 90–140 m/min and generous coolant — vanadium carbides accelerate tool wear.
Can 21CrMoV5-7 be welded?
Weldable with matched Cr-Mo-V or 2.25Cr-1Mo consumables using 250–350 °C preheat/interpass and mandatory PWHT at ~690–720 °C; avoid welding fully tempered bolts.
Can 21CrMoV5-7 be formed, bent or molded?
Forge at 1100–850 °C followed by normalizing; cold heading only in the spheroidized condition, then quench (880–930 °C, oil) and temper 660–720 °C.
21CrMoV5-7 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| C | 0.17 – 0.25 | 0.21 |
| Si | ≤ 0.35 | 0.25 |
| Mn | 0.4 – 0.8 | 0.6 |
| P | ≤ 0.03 | 0.01 |
| S | ≤ 0.02 | 0.01 |
| Cr | 1.2 – 1.5 | 1.35 |
| Mo | 0.5 – 0.7 | 0.6 |
| V | 0.25 – 0.35 | 0.3 |
| Niresidual, max | ≤ 0.5 | 0.2 |
| Alacid-soluble, max (grain refining) | ≤ 0.02 | 0.01 |
| Fe | balance |
What surface finishes work on 21CrMoV5-7?
No natural corrosion protection — use phosphating plus MoS₂/graphite bolt lubricant, aluminizing or nickel plating for high-temperature service; avoid electroplating without hydrogen bake-out.
Surface treatments FabDigit runs on steel parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Organic Coating
Black / Phosphate
Thermal Spray
Equivalent designations
Standards and trade names that resolve to Steel 21CrMoV5-7 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 1.7709
How much does 21CrMoV5-7 cost?
21CrMoV5-7 is a standard-cost steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
21CrMoV5-7 — frequently asked
What is 21CrMoV5-7 used for?
21CrMoV5-7 is typically used for steam turbine bolts and shafts, high-pressure valve bodies, boiler and pipeline fittings and power plant fasteners. In short: high-temperature bolting steel; creep resistant to 540 °C.
What is the yield strength of 21CrMoV5-7?
21CrMoV5-7 has a typical yield strength of 700 MPa (102 ksi) and a tensile strength of 830 MPa (120 ksi) — stronger than 81% of steel grades. Strength varies by condition: see the 5 listed tempers.
Is 21CrMoV5-7 easy to machine?
Not especially — machinability is rated fair (42/100, worse than 73% of steel grades). Machine in +AC/+A condition where possible; in +QT (≈250 HB) use rigid setups, carbide inserts at 90–140 m/min and generous coolant — vanadium carbides accelerate tool wear.
Can 21CrMoV5-7 be welded?
With care — weldability is rated fair (35/100). Weldable with matched Cr-Mo-V or 2.25Cr-1Mo consumables using 250–350 °C preheat/interpass and mandatory PWHT at ~690–720 °C; avoid welding fully tempered bolts.
What surface finishes work on 21CrMoV5-7?
No natural corrosion protection — use phosphating plus MoS₂/graphite bolt lubricant, aluminizing or nickel plating for high-temperature service; avoid electroplating without hydrogen bake-out.
Can 21CrMoV5-7 be formed, bent or molded?
Forge at 1100–850 °C followed by normalizing; cold heading only in the spheroidized condition, then quench (880–930 °C, oil) and temper 660–720 °C.
What is the maximum service temperature of 21CrMoV5-7?
21CrMoV5-7 is rated for continuous use to about 540°C (1,004 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 21CrMoV5-7 cost?
21CrMoV5-7 is a standard-cost steel ($$), cheaper than about 71% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- EN 10269 — Steels and nickel alloys for fasteners with specified elevated and/or low temperature properties — CEN (2013)
- EN 10222-2 — Steel forgings for pressure purposes: ferritic and martensitic steels for elevated temperature — CEN (2017)
- EN 10269 / DIN 17240 legacy data for 21CrMoV5-7 (1.7709) — DIN (1976)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.19 — Fatigue and Fracture — ASM International (1996)
- Cr-Mo-V bolting steel 1.7709 bar/forging datasheet — European special steel producers (e.g. Böhler/Saarstahl-type data) (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.