Steel 17CrNiMo6 +TH
Hardness band
EN 17CrNiMo6
+TH = treated to a specified hardness range
Use when bar is ordered to an agreed hardness band near 205 HB, so dimensions and tool life stay predictable on automated turning lines in volume production.
Values for the +TH condition
Other 17CrNiMo6 tempers and conditions
17CrNiMo6 is listed in 7 conditions; see the grade overview at 17CrNiMo6.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Treated to ferrite-pearlite structure | Choose when a controlled ferrite-pearlite structure at about 175 HB is needed for consistent cutting behaviour and good machined surface quality on precision gear blanks. | 390 | 620 | 22 | 175 HB | 8.5 % IACS |
AnnealedDefault soft annealed (≤229 HB), machining condition | Pick the usual supply state — soft annealed bar or forgings at ≤229 HB — for rough turning and gear hobbing before carburizing and quenching to the final case hardness. | 430 | 700 | 20 | 200 HB | — |
+THThis page Treated to a specified hardness range | Use when bar is ordered to an agreed hardness band near 205 HB, so dimensions and tool life stay predictable on automated turning lines in volume production. | 450 | 720 | 18 | 205 HB | 8 % IACS |
Treated for shearability | Pick for cold shear cut-off and cold forging or upsetting, where the softening treatment for shearability prepares bar stock at about 225 HB for gear blank forging. | 480 | 780 | 16 | 20 HRC | 8 % IACS |
normalized bar/forging | Choose after forging to refine and homogenize the structure at about 260 HB; use as an intermediate state before rough machining, quench and temper, or carburizing. | 560 | 880 | 15 | 26 HRC | 8 % IACS |
Hot Rolled / as-rolled (+U, untreated) | Pick the untreated as-rolled bar as the cheapest starting stock only when forging or a full heat-treatment cycle follows, since 270 HB makes machining more difficult. | 560 | 900 | 14 | 27 HRC | 8 % IACS |
Carburized, hardened & tempered | Choose as the final service condition: carburized, hardened and tempered to a 58–62 HRC case over a tough core for heavy gear flank contact and tooth-root bending fatigue. | 900 | 1,200 | 9 | 60 HRC | — |
What is 17CrNiMo6 +TH?
17CrNiMo6 +TH is 17CrNiMo6 heat treated to +TH — use when bar is ordered to an agreed hardness band near 205 HB, so dimensions and tool life stay predictable on automated turning lines in volume production. 17CrNiMo6 +TH has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 52% of steel grades. Elongation at break is 18% and the elastic modulus is 210 GPa (30.5 Msi). 17CrNiMo6 +TH has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F). Annealed is the default condition FabDigit quotes; +TH is available on request or by drawing note.
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 +TH properties
Typical room-temperature values for 17CrNiMo6 +TH; 22 are specific to this condition. Other listed values are 17CrNiMo6 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
17CrNiMo6 +TH has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,420°C (2,588 °F).
Mechanical14
17CrNiMo6 +TH has a yield strength of 450 MPa (65.3 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 52% of steel grades. Elongation at break is 18% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
17CrNiMo6 +TH is rated for continuous service to 200°C (392 °F). It conducts heat at 38 W/m·K (22 BTU/hr·ft·°F), worse than 69% of steel grades. Thermal expansion is 11.5 µm/m·K (6.39 µin/in·°F).
Electrical3
17CrNiMo6 +TH conducts electricity at 8 % IACS, better than 55% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (12/100), worse than 53% of steel grades.
Sustainability4
Producing a kilogram of 17CrNiMo6 +TH takes about 32 MJ of energy and emits 2.3 kg of CO₂ — more than 70% of steel grades. Typical recycled content is 30%.
Manufacturability8
17CrNiMo6 +TH's machinability is fair (52/100, better than 52% of steel grades); weldability poor (30/100); formability fair (40/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 17CrNiMo6 +TH
Is 17CrNiMo6 easy to machine?
In the annealed condition (≤229 HB) turn, mill and hob normally with coated carbide; after carburizing and quenching only grinding or CBN hard turning is practical.
Can 17CrNiMo6 be welded?
Poor weldability: high carbon equivalent and cold-cracking sensitivity require 250-350 °C preheat, low-hydrogen consumables and prompt post-heat for hydrogen removal; do not weld in carburized areas.
Can 17CrNiMo6 be formed, bent or molded?
Suited to hot forging and hot rolling at 1100-1250 °C, followed by normalizing or annealing; cold formability is limited to cold shearing and light upsetting/extrusion in the +S condition.
What surface finishes work on 17CrNiMo6?
Cannot be anodized. Usual route is gear grinding plus shot peening to raise root fatigue strength, then black oxide, phosphating or rust-preventive oil; non-tooth surfaces can be zinc-nickel plated or painted.
17CrNiMo6 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 |
|---|---|---|
| C0.15–0.20 per DIN 17210 (17CrNiMo6); 0.15–0.21 per EN 10084 (18CrNiMo7-6) | 0.15 – 0.21 | 0.18 |
| Si | ≤ 0.4 | 0.25 |
| Mn0.40–0.60 per old DIN 17210; 0.50–0.90 per EN 10084 | 0.4 – 0.9 | 0.65 |
| P≤0.035 per older DIN | ≤ 0.03 | — |
| Scontrolled-S variants 0.020–0.035 for machinability | ≤ 0.04 | — |
| Cr | 1.5 – 1.8 | 1.65 |
| Ni | 1.4 – 1.7 | 1.55 |
| Mo | 0.25 – 0.35 | 0.3 |
| Fe | balance | — |
17CrNiMo6 +TH — frequently asked
What is 17CrNiMo6 +TH used for?
17CrNiMo6 +TH is typically used for gears, industrial drive shafts and pins. In short: premium carburizing gear steel.
What is the yield strength of 17CrNiMo6 +TH?
17CrNiMo6 +TH has a typical yield strength of 450 MPa (65.3 ksi) and a tensile strength of 720 MPa (104 ksi) — stronger than 52% of steel grades. Strength varies by condition: see the 7 listed tempers.
Is 17CrNiMo6 +TH easy to machine?
Reasonably — machinability is rated fair (52/100, better than 52% of steel grades). In the annealed condition (≤229 HB) turn, mill and hob normally with coated carbide; after carburizing and quenching only grinding or CBN hard turning is practical.
Can 17CrNiMo6 +TH be welded?
Not readily — weldability is rated poor (30/100). Poor weldability: high carbon equivalent and cold-cracking sensitivity require 250-350 °C preheat, low-hydrogen consumables and prompt post-heat for hydrogen removal; do not weld in carburized areas.
What surface finishes work on 17CrNiMo6 +TH?
Cannot be anodized. Usual route is gear grinding plus shot peening to raise root fatigue strength, then black oxide, phosphating or rust-preventive oil; non-tooth surfaces can be zinc-nickel plated or painted.
Can 17CrNiMo6 +TH be formed, bent or molded?
Suited to hot forging and hot rolling at 1100-1250 °C, followed by normalizing or annealing; cold formability is limited to cold shearing and light upsetting/extrusion in the +S condition.
What is the maximum service temperature of 17CrNiMo6 +TH?
17CrNiMo6 +TH 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.
Can FabDigit make parts in 17CrNiMo6 +TH?
Yes — 17CrNiMo6 +TH is available for CNC machining and sheet metal; every part is priced by an engineer rather than instantly. Upload a STEP file to get a price and a DFM check.
Sources
- EN 10084 — Case hardening steels: technical delivery conditions — CEN (2008)
- DIN 17210 (withdrawn) — Case hardening steels (17CrNiMo6) — DIN (1987)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels, and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4A — Steel Heat Treating Fundamentals (carburizing) — ASM International (2013)
- 18CrNiMo7-6 / 1.6587 gear steel datasheet — Ovako / Böhler-Deutschland (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.