Steel 17CrNiMo6-4
EN 17CrNiMo6-4
17CrNiMo6-4 (1.6566) is a European Ni-Cr-Mo carburizing steel that sits between 16MnCr5 and 18CrNiMo7-6 in alloy content, used for medium to heavy-duty gearing.
Reference datasheet — 17CrNiMo6-4 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 +A condition
17CrNiMo6-4 tempers and conditions
17CrNiMo6-4 is supplied in 8 conditions, soft to hard. +A 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 |
|---|---|---|---|---|---|---|
Treated for cold shearing | Use for cold shearing of wire and bar cut-offs, where the capped hardness of about 175 HB and 620 MPa tensile prevents shear cracking at the cost of strength. | 380 | 620 | 19 | 175 HB | 7.8 % IACS |
Treated to ferrite-pearlite structure and hardness range | Pick the controlled ferrite-pearlite structure and hardness band (about 170 HB) when automatic machining lines need predictable chip formation and stable tool life before carburizing. | 390 | 620 | 19 | 170 HB | 7.8 % IACS |
Treated to specified hardness range | Order to a contractually agreed hardness range (about 180 HB, 640 MPa tensile) when high-volume machining ahead of case hardening requires batch-to-batch consistency. | 395 | 640 | 18 | 180 HB | 7.8 % IACS |
+ADefault Annealed | Choose the soft-annealed (spheroidized, ≤229 HB) bar or forging blank for rough turning, gear hobbing and cold forming, before the parts are carburized and quenched. | 400 | 650 | 18 | 185 HB | 7.8 % IACS |
Normalized | Pick normalized forgings to refine grain and homogenize the structure as a preparatory treatment before carburizing; the 225 HB level reduces machinability. | 500 | 780 | 15 | 19 HRC | 7.7 % IACS |
Cold drawn | Choose annealed-then-cold-drawn bright bar in small diameters for tight size tolerance and minimal finish-turning allowance; drawing lifts strength but cuts elongation to 10%. | 580 | 760 | 10 | 18 HRC | 7.8 % IACS |
Blank-hardened (quenched & tempered without carburizing), core… | Use blank hardening — quenched and tempered without carburizing — to qualify core strength or for high-strength shafts at 1150 MPa and 350 HB, accepting poor machining and welding. | 830 | 1,150 | 10 | 37 HRC | — |
Carburized and hardened | Specify carburized, quenched and low-temperature tempered parts as the final gear and shaft state: a 58–62 HRC case resists pitting and wear over a tough core, with no machining left. | 830 | 1,150 | 9 | 60 HRC | — |
What is 17CrNiMo6-4?
17CrNiMo6-4 (1.6566) is a European Ni-Cr-Mo carburizing steel that sits between 16MnCr5 and 18CrNiMo7-6 in alloy content, used for medium to heavy-duty gearing. In the default condition it offers 400 MPa yield, 650 MPa tensile, 18% elongation and about 185 HB, with machinability 58 and formability 60, and is available as +A, +FP, +TH, +S, +N, +C and blank- or case-hardened bar and forgings. Hardenability makes welding restrictive and the steel has no corrosion resistance, so a protective finish or oil film is needed. Choose 18CrNiMo7-6 for deeper cases and larger sections, or 16MnCr5 for lower-cost small gears. 17CrNiMo6-4 has a density of 7.84 g/cm³ (0.283 lb/in³), lighter than 78% of steel grades. It melts at 1,420°C (2,588 °F). 17CrNiMo6-4 has a yield strength of 400 MPa (58 ksi) and a tensile strength of 650 MPa (94.3 ksi) — weaker than 60% of steel grades. Elongation at break is 18% and the elastic modulus is 210 GPa (30.5 Msi).
What is 17CrNiMo6-4 used for?
- Automotive transmission gears
- Industrial gearbox gears and pinions
- Wind turbine gearbox components
- Splined shafts
- Ring and bevel gears
- Heavy-duty gear blanks
Advantages
- Polishes to a fine finish — 65/100, better than 78% of steel grades
Limitations
- Limited service temperature — 200°C (392 °F), worse than 93% of steel grades
17CrNiMo6-4 properties
Typical room-temperature values for 17CrNiMo6-4-+A; bars are the position among steel grades.
Physical3
17CrNiMo6-4 has a density of 7.84 g/cm³ (0.283 lb/in³), lighter than 78% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical16
17CrNiMo6-4 has a yield strength of 400 MPa (58 ksi) and a tensile strength of 650 MPa (94.3 ksi) — weaker than 60% of steel grades. Elongation at break is 18% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
17CrNiMo6-4 is rated for continuous service to 200°C (392 °F). It conducts heat at 44 W/m·K (25.4 BTU/hr·ft·°F), better than 57% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
17CrNiMo6-4 conducts electricity at 7.8 % IACS, worse than 57% of steel grades.
Chemical & Environmental2
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 17CrNiMo6-4 takes about 34 MJ of energy and emits 2.3 kg of CO₂ — more than 82% of steel grades. Typical recycled content is 30%.
Manufacturability6
17CrNiMo6-4's machinability is good (58/100, better than 75% of steel grades); weldability fair (45/100); formability good (60/100).
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. 17CrNiMo6-4 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 17CrNiMo6-4
Is 17CrNiMo6-4 easy to machine?
Turning, milling and hobbing run well in the annealed (+A) or ferrite-pearlite (+FP) condition. After carburizing and quenching, only grinding or CBN hard turning is practical.
Can 17CrNiMo6-4 be welded?
The low carbon content allows welding, but the Ni-Cr-Mo composition hardens readily: preheat 150–250 °C, use low-hydrogen consumables and stress relieve after welding. Do not weld in carburized areas.
Can 17CrNiMo6-4 be formed, bent or molded?
Hot forge 1050–1150 °C; in the soft-annealed condition the steel also takes cold heading and cold extrusion. Normalize or anneal after forming and before carburizing.
17CrNiMo6-4 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 |
|---|---|---|
| CEN 10084 (17NiCrMo6-4 / 1.6566) | 0.14 – 0.2 | 0.17 |
| Si | ≤ 0.4 | 0.25 |
| Mn | 0.6 – 0.9 | 0.75 |
| Pimpurity maximum | ≤ 0.03 | |
| Sin +S condition may be 0.020–0.040 | ≤ 0.04 | |
| Cr | 0.8 – 1.1 | 0.95 |
| Mo | 0.15 – 0.25 | 0.2 |
| Ni | 1.2 – 1.5 | 1.35 |
| Fe | balance |
What surface finishes work on 17CrNiMo6-4?
After carburizing and grinding, parts can be black oxided, phosphated, zinc plated or shot peened — shot peening significantly increases tooth-root bending fatigue life. There is no inherent corrosion resistance, so rust protection is required.
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 17CrNiMo6-4 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- EN / DIN / Werkstoff-Nr.
- 1.6566
How much does 17CrNiMo6-4 cost?
17CrNiMo6-4 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.
17CrNiMo6-4 — frequently asked
What is 17CrNiMo6-4 used for?
17CrNiMo6-4 is typically used for automotive transmission gears, industrial gearbox gears and pinions, wind turbine gearbox components, splined shafts, ring and bevel gears and heavy-duty gear blanks. In short: mid-range Ni-Cr-Mo case steel; good core toughness; between 16MnCr5 and 18CrNiMo7-6.
What is the yield strength of 17CrNiMo6-4?
17CrNiMo6-4 has a typical yield strength of 400 MPa (58 ksi) and a tensile strength of 650 MPa (94.3 ksi) — weaker than 60% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 17CrNiMo6-4 easy to machine?
Reasonably — machinability is rated good (58/100, better than 75% of steel grades). Turning, milling and hobbing run well in the annealed (+A) or ferrite-pearlite (+FP) condition. After carburizing and quenching, only grinding or CBN hard turning is practical.
Can 17CrNiMo6-4 be welded?
With care — weldability is rated fair (45/100). The low carbon content allows welding, but the Ni-Cr-Mo composition hardens readily: preheat 150–250 °C, use low-hydrogen consumables and stress relieve after welding. Do not weld in carburized areas.
What surface finishes work on 17CrNiMo6-4?
After carburizing and grinding, parts can be black oxided, phosphated, zinc plated or shot peened — shot peening significantly increases tooth-root bending fatigue life. There is no inherent corrosion resistance, so rust protection is required.
Can 17CrNiMo6-4 be formed, bent or molded?
Hot forge 1050–1150 °C; in the soft-annealed condition the steel also takes cold heading and cold extrusion. Normalize or anneal after forming and before carburizing.
What is the maximum service temperature of 17CrNiMo6-4?
17CrNiMo6-4 is rated for continuous use to about 200°C (392 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 17CrNiMo6-4 +A and 17CrNiMo6-4-BH?
+A is the default condition — choose the soft-annealed (spheroidized, ≤229 HB) bar or forging blank for rough turning, gear hobbing and cold forming, before the parts are carburized and quenched. BH: use blank hardening — quenched and tempered without carburizing — to qualify core strength or for high-strength shafts at 1150 MPa and 350 HB, accepting poor machining and welding. Yield strength is 400 MPa in +A versus 830 MPa in BH.
How much does 17CrNiMo6-4 cost?
17CrNiMo6-4 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 10084 — Case hardening steels: technical delivery conditions — CEN (2008)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
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.