20MnCr5 is a case-hardening steel with 0.17–0.22% carbon, 1.1–1.4% manganese and 1.0–1.3% chromium. The low carbon keeps the core tough while carburising gives a hard surface. After case hardening, the core delivers 1,200–1,500 MPa tensile strength and 850 MPa minimum yield at Ø 11 mm, 1,000–1,300 MPa at Ø 30 mm and 800–1,100 MPa at Ø 63 mm. Engineers choose it for gears and pinions, transmission shafts, camshafts, crown wheels, splined shafts and differential parts.
OneKaizen sources 20MnCr5 from India's leading mills and international partner mills and supplies it as rolled round bars in Ø 16–500 mm, bright bars in Ø 8–160 mm, forged bars in Ø 250–1,030 mm, gear blanks in 100–1,000 mm outside diameter and shafts in Ø 25–500 mm. Delivery condition is your choice: hot rolled, soft annealed, normalised, annealed to BS (+BF / +FP) or peeled and turned. Every consignment ships with a mill test certificate.
EQUIVALENT GRADES
20MnCr5 Equivalents
Direct means the same grade under another name. Close means the same alloy concept with slightly different limits, commonly substituted. Approximate means similar use with real differences: check with us before substituting.
| Standard | Designation | Match |
|---|---|---|
| EN | 20MnCr5 (1.7147) | Direct |
| EN | 20MnCrS5 (1.7149) | Close |
| DIN W.Nr. | 1.7147 | Direct |
| AISI/SAE | 5120 | Approximate |
| JIS | SMnC420 | Approximate |
| GB | 20CrMn | Close |
| UNI | 20MnCr5 | Direct |
| UNE | 20MnCr5 | Direct |
| TS | 20MnCr5 | Direct |
20MnCr5 Chemical Composition
Per EN 10084 (20MnCr5)
| Element | Range, wt % | Range chart |
|---|---|---|
| C | 0.17 – 0.22 | |
| Si | ≤ 0.4 | |
| Mn | 1.1 – 1.4 | |
| P | ≤ 0.025 | |
| S | ≤ 0.035 | |
| Cr | 1 – 1.3 |
20MnCr5 and Its Equivalents: Chemical Composition
Equivalent grades are written to different standards, so their limits differ slightly. Use the column for the standard on your drawing or purchase order.
| Element | 20MnCr5 EN 10084 | 20MnCrS5 EN 10084 | 20CrMn GB/T 3077 |
|---|---|---|---|
| C % | 0.17–0.22 | 0.17–0.22 | 0.17–0.23 |
| Si % | ≤ 0.40 | ≤ 0.40 | 0.17–0.37 |
| Mn % | 1.10–1.40 | 1.10–1.40 | 0.90–1.20 |
| P % | ≤ 0.025 | ≤ 0.025 | ≤ 0.035 |
| S % | ≤ 0.035 | 0.02–0.04 | ≤ 0.035 |
| Cr % | 1.00–1.30 | 1.00–1.30 | 0.90–1.20 |
20MnCr5 Mechanical Properties
| Condition | Tensile, MPa | Yield min, MPa | Elongation min, % | Hardness |
|---|---|---|---|---|
| Core, case hardened, d = 11 mm | 1200 – 1500 | 850 | 7 | – |
| Core, case hardened, d = 30 mm | 1000 – 1300 | 685 | 8 | – |
| Core, case hardened, d = 63 mm | 800 – 1100 | 590 | 10 | – |
Delivery Condition and Heat Treatment
20MnCr5 is delivered soft so you can machine the part before case hardening. In the soft annealed or annealed to BS condition it cuts and hobs easily. Typical practice is to carburise at about 880–950 °C, quench and temper at a low temperature, which gives a surface hardness of around 58–62 HRC over a tough core.
Core strength depends on the section. A Ø 11 mm part reaches 1,200–1,500 MPa; a Ø 63 mm part reaches 800–1,100 MPa, because the core cools more slowly in larger sections. Choose the bar diameter with this in mind. For heavy sections, 18CrNiMo7-6 is the usual step up.
Do all machining and hobbing before carburising. Do not weld after case hardening, because the hard case cracks. In the low-carbon delivered condition the steel can be welded with preheat, but gear parts are normally not welded.
What We Supply 20MnCr5 In
Where 20MnCr5 Is Used
Industries: Automotive, Gearbox and transmission, Industrial machinery, Mining and construction equipment, Agricultural equipment
Compare 20MnCr5 with Similar Grades
| 20MnCr5 | 16MnCr5 | SAE 8620 | 18CrNiMo7-6 | |
|---|---|---|---|---|
| Why consider it | This grade | Lower carbon, tougher core | Ni-Cr-Mo alternative | Heavy sections |
| C % | 0.17–0.22 | 0.14–0.19 | 0.18–0.23 | 0.15–0.21 |
| Si % | ≤ 0.4 | ≤ 0.4 | 0.15–0.35 | ≤ 0.4 |
| Mn % | 1.1–1.4 | 1–1.3 | 0.7–0.9 | 0.5–0.9 |
| Cr % | 1–1.3 | 0.8–1.1 | 0.4–0.6 | 1.5–1.8 |
| Ni % | – | – | 0.4–0.7 | 1.4–1.7 |
| Mo % | – | – | 0.15–0.25 | 0.25–0.35 |
20MnCr5 Questions
What is the difference between 16MnCr5 and 20MnCr5?
20MnCr5 has more carbon (0.17–0.22% against 0.14–0.19%) and so higher core strength. At Ø 30 mm the core reaches 1,000–1,300 MPa against 800–1,100 MPa for 16MnCr5. 16MnCr5 gives a tougher core; 20MnCr5 suits heavier loads.
Is 20MnCr5 the same as SAE 8620?
No. SAE 8620 is a nickel-chromium-molybdenum steel and 20MnCr5 contains no nickel or molybdenum. 8620 is the usual alternative where you need deeper hardening in larger sections. Tell us which one your drawing specifies.
Is 20MnCr5 the same as SAE 5120 or JIS SMnC420?
Neither is an exact match. SAE 5120 and JIS SMnC420 are approximate equivalents, and there is no exact SAE equivalent. Check the chemistry limits against your drawing; tell us if you need the exact EN 10084 chemistry.
What surface hardness does 20MnCr5 reach after carburising?
Around 58–62 HRC at the surface, over a tough core. Case depth depends on carburising time and temperature. Tell us the case depth and core strength you need and we supply the right bar and condition.
Can 20MnCr5 be machined before heat treatment?
Yes, and that is the intended route. We supply it soft annealed or annealed to BS (+BF / +FP) for machining and hobbing. Machine to near final size, then carburise and finish grind.
What is the minimum order for 20MnCr5?
3 tonnes, flexible depending on grade, size and your situation. Round bars, forged bars, gear blanks and shafts are supplied on request; send us your size, condition and quantity.
What is 20MnCr5 equivalent to?
20MnCr5 is the same grade as EN 20MnCr5, DIN W.Nr. 1.7147, UNI 20MnCr5, UNE 20MnCr5. Close equivalents are EN 20MnCrS5, GB 20CrMn.
In which forms do you supply 20MnCr5?
OneKaizen supplies 20MnCr5 as Round Bars, Forged Bars, Gear Blanks, Bright Bars, Shafts, delivered across India and exported to buyers abroad.
Do you supply 20MnCr5 with a mill test certificate?
Yes. Every lot ships with an EN 10204 3.1 mill test certificate showing chemistry and mechanical properties, traceable to the heat number.
Data compiled by the OneKaizen metallurgy team from the standards named above. Updated 26 October 2026. Equivalents are nearest matches; confirm critical substitutions against the governing standard and mill certificate.