Steel 20MnCr5-TH
Hardness band
EN 20MnCr5
Ordered when a narrow bar hardness band is needed for stable automatic machining.
Values for the TH condition
Other 20MnCr5 tempers and conditions
20MnCr5 is listed in 8 conditions; see the grade overview at 20MnCr5.
Compare all 8 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
soft/spheroidize annealed (+A) | Softest condition, max hardness 217 HB — choose for heavy machining or cold forging of blanks. | 350 | 560 | 24 | 170 HB | — |
THThis page treated to hardness range (machinability-controlled delivery) | Ordered when a narrow bar hardness band is needed for stable automatic machining. | 390 | 620 | 21 | 10 HRC | 8.4 % IACS |
~880–920 °C, air cool | Uniform fine ferrite–pearlite structure before machining and carburizing; reduces distortion scatter. | 420 | 680 | 20 | 190 HB | — |
HRDefault Hot rolled | Standard stock condition for gear blanks that will be machined then carburized. | 460 | 750 | 18 | 210 HB | — |
Cold rolled | Thin strip for stamped/deep-drawn parts that will be carburized (chain plates, small gears). | 560 | 720 | 10 | 17 HRC | 8.2 % IACS |
Cold drawn | Bright, size-accurate bar for automatic-lathe parts and shafts; higher strength, lower ductility. | 620 | 800 | 10 | 20 HRC | 8.2 % IACS |
Quenched and tempered | Through-hardened core condition (no carburizing) for medium-strength shafts; core values per EN 10084 for 11–30 mm sections. | 750 | 1,000 | 12 | 32 HRC | — |
Carburized and hardened | The service condition for gears: 58–62 HRC case over a tough 30–40 HRC core, high contact and bending fatigue strength. | 780 | 1,050 | 11 | 60 HRC | — |
What is 20MnCr5-TH?
20MnCr5-TH is 20MnCr5 heat treated to TH — ordered when a narrow bar hardness band is needed for stable automatic machining. 20MnCr5-TH has a yield strength of 390 MPa (56.6 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 64% of steel grades. Elongation at break is 21% and the elastic modulus is 210 GPa (30.5 Msi). 20MnCr5-TH has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F). HR is the default condition FabDigit quotes; TH is available on request or by drawing note.
Advantages
- Easy to machine — 65/100, better than 93% of steel grades
- Forms and bends easily — 65/100, better than 81% of steel grades
Limitations
- Limited service temperature — 250°C (482 °F), worse than 85% of steel grades
20MnCr5-TH properties
Typical room-temperature values for 20MnCr5-TH; 23 are specific to this condition. Other listed values are 20MnCr5 reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
20MnCr5-TH has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,425°C (2,597 °F).
Mechanical15
20MnCr5-TH has a yield strength of 390 MPa (56.6 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 64% of steel grades. Elongation at break is 21% and the elastic modulus is 210 GPa (30.5 Msi).
Thermal6
20MnCr5-TH is rated for continuous service to 250°C (482 °F). It conducts heat at 45 W/m·K (26 BTU/hr·ft·°F), better than 66% of steel grades. Thermal expansion is 11.1 µm/m·K (6.17 µin/in·°F).
Electrical3
20MnCr5-TH conducts electricity at 8.4 % IACS, better than 62% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of 20MnCr5-TH takes about 27 MJ of energy and emits 2.1 kg of CO₂ — less than 59% of steel grades. Typical recycled content is 30%.
Manufacturability8
20MnCr5-TH's machinability is good (65/100, better than 93% of steel grades); weldability fair (50/100); formability good (65/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 20MnCr5-TH
Is 20MnCr5 easy to machine?
Machine in the annealed or normalized state with carbide tooling (≈60% of 1212); finish-grind after carburizing since 60 HRC case is essentially unmachinable.
Can 20MnCr5 be welded?
Weldable only before carburizing — preheat 200–250 °C, low-hydrogen consumables, post-weld stress relief; never weld a case-hardened surface.
Can 20MnCr5 be formed, bent or molded?
Good hot forgeability at 1100–1200 °C and good cold-heading behaviour after spheroidize annealing; normalize after forging before machining.
What surface finishes work on 20MnCr5?
No anodizing; protect with oil, black oxide, Mn-phosphate or zinc plating (bake for hydrogen relief), and shot-peen gear roots to boost bending fatigue.
20MnCr5 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 | 0.17 – 0.22 | 0.2 |
| Si | ≤ 0.4 | 0.25 |
| Mn | 1.1 – 1.4 | 1.25 |
| Cr | 1 – 1.3 | 1.15 |
| P | ≤ 0.03 | 0.02 |
| S0.020–0.040 for the +S free-machining variant | ≤ 0.04 | 0.02 |
| Fe | balance | — |
20MnCr5-TH — frequently asked
What is 20MnCr5-TH used for?
20MnCr5-TH is typically used for gears, industrial drive shafts and pins. In short: carburizing Cr-Mn bar.
What is the yield strength of 20MnCr5-TH?
20MnCr5-TH has a typical yield strength of 390 MPa (56.6 ksi) and a tensile strength of 620 MPa (89.9 ksi) — weaker than 64% of steel grades. Strength varies by condition: see the 8 listed tempers.
Is 20MnCr5-TH easy to machine?
Reasonably — machinability is rated good (65/100, better than 93% of steel grades). Machine in the annealed or normalized state with carbide tooling (≈60% of 1212); finish-grind after carburizing since 60 HRC case is essentially unmachinable.
Can 20MnCr5-TH be welded?
With care — weldability is rated fair (50/100). Weldable only before carburizing — preheat 200–250 °C, low-hydrogen consumables, post-weld stress relief; never weld a case-hardened surface.
What surface finishes work on 20MnCr5-TH?
No anodizing; protect with oil, black oxide, Mn-phosphate or zinc plating (bake for hydrogen relief), and shot-peen gear roots to boost bending fatigue.
Can 20MnCr5-TH be formed, bent or molded?
Good hot forgeability at 1100–1200 °C and good cold-heading behaviour after spheroidize annealing; normalize after forging before machining.
What is the maximum service temperature of 20MnCr5-TH?
20MnCr5-TH is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 20MnCr5-HR and 20MnCr5-CH?
HR is the default condition — standard stock condition for gear blanks that will be machined then carburized. CH: the service condition for gears: 58–62 HRC case over a tough 30–40 HRC core, high contact and bending fatigue strength. Yield strength is 460 MPa in HR versus 780 MPa in CH.
Can FabDigit make parts in 20MnCr5-TH?
Yes — 20MnCr5-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)
- EN 10277 — Bright steel products — CEN (2018)
- GB/T 3077 (20CrMn/20CrMnH ) — SAC (2015)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels and High-Performance Alloys — ASM International (1990)
- ASM Handbook Vol.4 — Heat Treating (carburizing of Mn-Cr steels) — ASM International (1991)
- Case hardening steel 20MnCr5 (1.7147) bar datasheet — Ovako / Böhler-Uddeholm (2021)
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.