Steel 30CrMoV9
EN 30CrMoV9 · also Nitralloy 135
30CrMoV9 (1.7707, Nitralloy 135) is a Cr-Mo-V nitriding steel covered by EN 10085, used where a tough quenched-and-tempered core must carry a hard nitrided case.
Reference datasheet — 30CrMoV9 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 +QT900 condition
30CrMoV9 tempers and conditions
30CrMoV9 is supplied in 8 conditions, soft to hard. +QT900 is the default FabDigit quotes; the values on this page are for it.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Pick for bar/forging stock that must be rough machined or cold worked before hardening. | 500 | 780 | 18 | 20 HRC | — |
Normalized | Pick for forgings needing a uniform fine-grained structure prior to final quench and temper. | 600 | 900 | 14 | 26 HRC | 7.8 % IACS |
+QT | Pick for heavy forgings and large-diameter bar where hardenability limits core strength. | 650 | 880 | 13 | 27 HRC | — |
Cold drawn, annealed | Pick for small-diameter bright bar with close tolerance where only light machining precedes hardening. | 650 | 850 | 12 | 24 HRC | 8 % IACS |
+QT900Default +QT | Most commonly stocked condition: general-purpose Q&T bar/forging ready for finish machining and nitriding. | 750 | 1,000 | 11 | 31 HRC | — |
+QT + gas/plasma nitrided | Pick for the final service condition: hard 0.2–0.6 mm nitrided case on a Q&T core for wear and bending fatigue. | 750 | 1,000 | 10 | 65 HRC | — |
+QT | Pick for medium shafts and gears; standard pre-nitriding condition for mid-size bar. | 850 | 1,100 | 11 | 35 HRC | — |
+QT | Pick for small-diameter shafts, pins and gear blanks where maximum core strength is needed. | 950 | 1,200 | 10 | 39 HRC | — |
What is 30CrMoV9?
30CrMoV9 (1.7707, Nitralloy 135) is a Cr-Mo-V nitriding steel covered by EN 10085, used where a tough quenched-and-tempered core must carry a hard nitrided case. It is supplied as bar, cold-drawn (CD+A) and forging stock in +A, +N, the +QT800 to +QT1100 tempers and +QT+NIT for gears, worm shafts and wear-loaded machine parts. The default quenched-and-tempered condition gives 750 MPa yield, 1000 MPa tensile, 11 % elongation and 305 HB (31 HRC), with machinability rated 40. It is effectively non-weldable and has no corrosion resistance; 34CrAlMo5 is the alternative nitriding grade and 42CrMo4 the choice where no case is needed. 30CrMoV9 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,430°C (2,606 °F). 30CrMoV9 has a yield strength of 750 MPa (109 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 84% of steel grades. Elongation at break is 11% and the elastic modulus is 210 GPa (30.5 Msi).
What is 30CrMoV9 used for?
- large gears
- worm shafts
- nitrided components
Advantages
- High service temperature — 450°C (842 °F), better than 86% of steel grades
- High strength — 750 MPa (109 ksi), better than 84% of steel grades
- Polishes to a fine finish — 65/100, better than 78% of steel grades
Limitations
- Limited ductility — 11%, worse than 89% of steel grades
- Difficult to weld — 22/100, worse than 81% of steel grades
- Limited formability — 20/100, worse than 80% of steel grades
- Poor heat conductor — 34 W/m·K (19.6 BTU/hr·ft·°F), worse than 77% of steel grades
- Difficult to machine — 40/100, worse than 77% of steel grades
30CrMoV9 properties
Typical room-temperature values for 30CrMoV9-+QT900; bars are the position among steel grades.
Physical3
30CrMoV9 has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,430°C (2,606 °F).
Mechanical16
30CrMoV9 has a yield strength of 750 MPa (109 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 84% of steel grades. Elongation at break is 11% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
30CrMoV9 is rated for continuous service to 450°C (842 °F). It conducts heat at 34 W/m·K (19.6 BTU/hr·ft·°F), worse than 77% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
30CrMoV9 conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental3
Corrosion resistance is poor (18/100), better than 83% of steel grades.
Sustainability4
Producing a kilogram of 30CrMoV9 takes about 34 MJ of energy and emits 2.4 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 30%.
Manufacturability8
30CrMoV9's machinability is fair (40/100, worse than 77% of steel grades); weldability poor (22/100); formability poor (20/100).
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. 30CrMoV9 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 30CrMoV9
Is 30CrMoV9 easy to machine?
Finish machine in the Q&T condition (280–330 HB) with coated carbide, rigid setups and generous coolant; leave 0.02–0.05 mm stock only for post-nitride lapping since the case cannot be turned.
Can 30CrMoV9 be welded?
Essentially non-weldable for structural joints — high C plus 2.5% Cr gives a hard, crack-prone HAZ; if unavoidable, preheat 300–350 °C, use low-hydrogen Cr-Mo consumables and temper immediately after welding, and never weld nitrided surfaces.
Can 30CrMoV9 be formed, bent or molded?
Hot forge 1100–850 °C followed by slow cool and soft anneal (~650–700 °C); cold forming is limited to light straightening in the annealed condition.
30CrMoV9 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 | 0.26 – 0.34 | 0.3 |
| Si | ≤ 0.4 | 0.25 |
| Mn | 0.4 – 0.7 | 0.55 |
| P | ≤ 0.03 | |
| Smax (lower for high-quality/vacuum-degassed bar) | ≤ 0.04 | |
| Cr | 2.3 – 2.7 | 2.5 |
| Mo | 0.15 – 0.25 | 0.2 |
| V | 0.1 – 0.2 | 0.15 |
| Fe | balance |
What surface finishes work on 30CrMoV9?
Gas or plasma nitride 500–530 °C for 0.2–0.6 mm case at ≥800 HV; grind/superfinish before nitriding, then only lap or polish. Phosphating, black oxide or hard chrome can be applied where corrosion protection is needed.
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 30CrMoV9 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 1.770710085
- Trade names
- Nitralloy 135
How much does 30CrMoV9 cost?
30CrMoV9 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.
30CrMoV9 — frequently asked
What is 30CrMoV9 used for?
30CrMoV9 is typically used for large gears, worm shafts and nitrided components. In short: cr-Mo-V nitriding gear steel; nitrided case above 800 HV; not weldable structurally.
What is the yield strength of 30CrMoV9?
30CrMoV9 has a typical yield strength of 750 MPa (109 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 84% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 30CrMoV9 easy to machine?
Not especially — machinability is rated fair (40/100, worse than 77% of steel grades). Finish machine in the Q&T condition (280–330 HB) with coated carbide, rigid setups and generous coolant; leave 0.02–0.05 mm stock only for post-nitride lapping since the case cannot be turned.
Can 30CrMoV9 be welded?
Not readily — weldability is rated poor (22/100). Essentially non-weldable for structural joints — high C plus 2.5% Cr gives a hard, crack-prone HAZ; if unavoidable, preheat 300–350 °C, use low-hydrogen Cr-Mo consumables and temper immediately after welding, and never weld nitrided surfaces.
What surface finishes work on 30CrMoV9?
Gas or plasma nitride 500–530 °C for 0.2–0.6 mm case at ≥800 HV; grind/superfinish before nitriding, then only lap or polish. Phosphating, black oxide or hard chrome can be applied where corrosion protection is needed.
Can 30CrMoV9 be formed, bent or molded?
Hot forge 1100–850 °C followed by slow cool and soft anneal (~650–700 °C); cold forming is limited to light straightening in the annealed condition.
What is the maximum service temperature of 30CrMoV9?
30CrMoV9 is rated for continuous use to about 450°C (842 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 30CrMoV9 cost?
30CrMoV9 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 10085 — Nitriding steels: technical delivery conditions — CEN (2001)
- DIN 17211 (superseded) / Werkstoff 1.7707 data — DIN (1987)
- ASM Handbook Vol. 1: Properties and Selection — Irons, Steels — ASM International (1990)
- ASM Handbook Vol. 4A: Steel Heat Treating Fundamentals (nitriding) — ASM International (2013)
- Nitriding steel 1.7707 / 30CrMoV9 bar datasheet — Böhler / Ovako / Lucchini (comparable producer sheets) (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.