Alloy Steel 20MnCr5 Round Bar
➡️ UNS G51200 | EN 1.7147 | AISI 5120 | ASTM A29
➡️ ASTM, EN, JIS & International Standards
➡️ Supply Conditions
➡️ Multiple Diameters & Supply Lengths
➡️ Global Export & International Delivery
Country of Origin:
Europe, Japan, USA
Material Type:
Alloy Steel
UNS Number:
G51200 / H51200
Wr. No.:
1.7147
MTC Available:
EN 10204 3.1
Product Description for Alloy Steel 20MnCr5 Round Bar
Alloy Steel 20MnCr5 Round Bar is a manganese-chromium case-hardening steel to EN 10084, with material number 1.7147. It contains about 0.17–0.22% carbon, 1.10–1.40% manganese and 1.00–1.30% chromium. It is one of the most common carburising steels in Europe and Asia for gears and transmission parts.
The steel has higher hardenability than 16MnCr5 because of its higher carbon, manganese and chromium. This gives higher core strength after carburising and makes it suitable for somewhat larger sections and more heavily loaded parts.
After carburising, quenching and tempering, the surface becomes hard and wear resistant, while the core keeps good toughness. The grade responds well to both gas carburising and carbonitriding. It has good machinability when supplied in the soft annealed (+A) or ferrite-pearlite (+FP) condition.
Bars are supplied hot rolled, forged, peeled or cold drawn. Common delivery conditions are untreated, treated for shearing (+S), soft annealed (+A), treated to hardness range (+TH) and ferrite-pearlite (+FP). The H-type grades, 20MnCr5+H, +HH and +HL, add hardenability bands for tighter heat treatment control.
Common applications include gears, gear shafts, crown wheels, pinions, camshafts, piston pins, spindles and other automotive and machinery parts that need a hard surface. It is often chosen as a cost-effective alternative to nickel-bearing carburising steels. 20MnCr5 is one of the most common case-hardening steels in European gear, axle and machine-building work. It is widely stocked as round bar in black, peeled and bright conditions, which helps keep lead times short and prices competitive for both small and large orders. Axle and transmission makers favour it for its steady heat-treatment response.
Common Applications of Alloy Steel 20MnCr5 Round Bar
➡️ Machined shafts, spindles, valve stems, pump sleeves and pins for food, beverage, dairy and pharmaceutical equipment, where the passive chromium oxide film resists both product acids and caustic clean-in-place chemicals.
➡️ Fasteners, studs, bolts, threaded rod and anchor components produced from bar stock, chosen for corrosion resistance combined with the ductility needed for cold heading and thread rolling.
➡️ Chemical, water treatment and general process plant parts such as agitator shafts, flange blanks, nozzles and support components handling water, steam and mildly corrosive media free of significant chlorides.
➡️ Architectural and structural hardware including handrail stanchions, balustrade fittings, tension rods and bollards, where a bright ground or polished bar finish provides both appearance and low maintenance.
International Equivalent Grade for 20MnCr5 Round Bar
Standard
Country / Region
Grade
UNS
USA
UNS G51200 / H51200
SAE / AISI
USA
SAE 5120 / AISI 5120
EN 10084
Europe
EN 1.7147 (20MnCr5)
BS
United Kingdom
527M20
JIS G4053
Japan
SMnC420H / SCr420H
GB/T 3077
China
20CrMn / 20CrMnTi / 20MnCr
KS
South Korea
SMnC420H
AFNOR
France
20MC5
GOST
Russia
18KhG (18ХГ)
ISO 683-3
International
20MnCr5
Technical Specification for Alloy Steel 20MnCr5 Round Bar
Specification
Value
Unit
Material
Alloy steel
-
Grade
20MnCr5 / 1.7147
-
Standard
EN 10084 (bright bars EN 10277)
-
Product Form
Round bar (hot rolled, forged or bright)
-
Diameter (supply range)
10–500
mm
Length (random)
3–6
m
Manufacturing Process
Hot rolled or forged, optional peeling, turning, cold drawing or grinding
-
Production Route
EAF or BOF + ladle refining + vacuum degassing
-
Surface Finish
Black, shot blasted, peeled, turned, cold drawn or ground
-
Heat Treatment / Delivery Condition
Untreated, +S, +A, +TH or +FP as ordered
-
Tolerance Standard
EN 10060 (hot rolled), EN 10278 (bright, h9-h11), ASTM A29 / A484 style tables for US orders
-
Carbon Equivalent CEV (IIW, calculated from mid-range analysis)
≈ 0.63
-
Density
7.85
g/cm³
Thermal Conductivity at 20°C
42
W/m·K
Coefficient of Thermal Expansion 20–100°C
11.5
µm/m·K
Specific Heat at 20°C
460
J/kg·K
Modulus of Elasticity at 20°C
210
GPa
Magnetic Properties
Ferromagnetic
-
Testing / Inspection
Chemical analysis, hardness, tensile and impact where specified, UT (EN 10308 / SEP 1921 / ASTM A388), grain size, Jominy on request
-
Certification
EN 10204 3.1 mill test certificate (3.2 on request)
-
Technical Specifications
Get the key technical specifications for Alloy Steel 20MnCr5 Round Bar
Alloy Steel 20MnCr5 Round Bar is ordered to EN 10084, which covers case-hardening steels. Bright bars can be ordered to EN 10277. The delivery condition must be stated, for example +A (soft annealed), +FP (ferrite-pearlite for machining) or +TH (treated to hardness range).
The H versions, 20MnCr5+H, +HH and +HL, add Jominy hardenability limits. These are often used in gear production to control distortion and core hardness.
Carburising is usually done at about 880–980°C, followed by quenching from about 830–870°C (core) or 780–820°C (case) and tempering at about 150–200°C. Actual cycles depend on the part and furnace.
The carbon equivalent shown is calculated from mid-range chemistry and is only a guide. The physical data for 20MnCr5 are reference values for Mn-Cr case-hardening steel. Standard testing covers heat analysis and hardness, with grain size, Jominy, inclusion rating and UT available on request.
For machining on automatic lathes, the +FP condition is often preferred because its ferrite-pearlite structure gives better chip control and more consistent tool life than +A. For gears, add the required hardenability band, grain size and cleanliness on the order. Bright bars to EN 10277 can be supplied in h9 to h11 tolerance for close machining.
Chemical Composition for Alloy Steel 20MnCr5 Round Bar
Element
Symbol
Min
Max
Unit
Carbon
C
0.17
0.22
%
Silicon
Si
-
0.40
%
Manganese
Mn
1.10
1.40
%
Phosphorus
P
-
0.025
%
Sulfur
S
-
0.035
%
Chromium
Cr
1.00
1.30
%
Chemical Composition
View the chemical composition and applicable material limits for 20MnCr5 Round Bar
The table shows the EN 10084 heat analysis limits for 20MnCr5. The +H grades use slightly wider limits combined with hardenability bands.
Carbon at 0.17–0.22% is low enough to keep the core tough, while the carburised surface reaches high carbon and high hardness. Manganese at 1.10–1.40% and chromium at 1.00–1.30% are the main alloying elements. Both raise hardenability, so the steel hardens more deeply and more evenly in oil quenching.
Chromium also forms hard carbides in the case, which improves wear resistance and surface fatigue strength in gears. Silicon acts as a deoxidiser.
Phosphorus is limited to 0.025%. Sulfur is allowed up to 0.035%, and a controlled sulfur range (20MnCrS5) can be ordered to improve machinability. Aluminium is often used for grain size control so the steel keeps a fine grain during carburising. Manganese at 1.10–1.40% and chromium at 1.00–1.30% give 20MnCr5 its good hardenability without costly nickel or molybdenum. Carbon at 0.17–0.22% keeps the core tough after case hardening. Sulfur can be ordered in a controlled range, for example 0.020–0.035%, to improve machinability, but this should be agreed with the supplier.
Mechanical Properties for Alloy Steel 20MnCr5 Round Bar
Mechanical Property
Value
Unit
Hardness (+A, soft annealed)
≤ 217
HB
Hardness (+FP, ferrite-pearlite)
152–201
HB
Core Tensile Strength (blank-hardened 30 mm)
980–1270
MPa
Core Yield Strength (blank-hardened 30 mm)
≥ 685
MPa
Core Elongation (blank-hardened 30 mm)
≥ 8
%
Case Hardness after carburising
58–62
HRC
Mechanical Properties
Check the key mechanical properties and performance requirements of 20MnCr5 Round Bar
For 20MnCr5, EN 10084 limits hardness in the supply condition instead of setting tensile values. For 20MnCr5, the +A and +FP hardness limits in the table are EN 10084 requirements for the delivered bar.
The 20MnCr5 core tensile values are reference figures for a 30 mm blank-hardened piece, taken from former DIN 17210 data. They show the strength level the core can reach after case hardening and are not mandatory EN 10084 limits.
Carburised and tempered 20MnCr5 gears normally reach about 58–62 HRC at the tooth surface. The actual core strength depends on section size, quench and tempering. For gear design, buyers should specify case depth, surface hardness and core hardness, and test them on representative samples. EN 10084 gives hardness limits for the delivery condition rather than fixed tensile values for the finished part, because final strength depends on the carburising and quenching cycle. The reference values shown apply to a test piece after blank hardening. For gears, the most useful checks are case depth, surface hardness, core hardness and retained austenite. Large sections have lower core hardness, so test at the correct position.
Retained austenite in the case should be kept low for gears.
Dimension / Sizes for Alloy Steel 20MnCr5 Round Bar
Dimension / Size
Value
Unit
Available Diameter Range (supply capability)
10–500 (forged sizes on request)
mm
Standard Length (random)
3–6
m
Custom / Cut-to-Length
Available on request
-
Diameter Tolerance
Hot rolled: EN 10060 or ASTM A29. Bright: EN 10278 (h9-h11) or as agreed
-
Length Tolerance
Per ordered standard or as agreed (commonly +50 / -0 mm for cut lengths)
-
Straightness Tolerance
Per EN 10060 / EN 10278 or as agreed
-
End Condition
Saw cut square, chamfered or as ordered
-
Surface Finish
Black (as rolled or forged), shot blasted, peeled, rough turned, cold drawn, centreless ground
-
Dimensions & Sizes
Explore available diameters, lengths, and dimensional requirements for 20MnCr5 Round Bar
Pricing for Alloy Steel 20MnCr5 Round Bar
Round Bar Prices are generally quoted per kilograms or meters tonnes and can fluctuate with the global raw material and market prices. The final price will depend on a variety of factors, including the grade size, diameter, length, surface finish, the quantity and whether the bars are cut to length or in standard lengths.
For smaller quantities, we can also quote per metre or per piece basis once the required dimensions have been confirmed. Container-loads or orders that are larger in size are typically priced per tonne, based upon the specifications required and the supply conditions.
Please provide your desired dimensions, grades, length number, and end for a current quote including the lead time applicable and details for certification.
Pricing
Get current Alloy Steel 20MnCr5 Round Bar pricing based on size, quantity, grade, finish, and delivery requirements.
Why Choose Us
Euro Steel Bars is an international distributor, stockist and exporter of stainless round steel bars that cover carbon, stainless alloy, special grades. We stock a variety of sizes and grades. We guarantee every order with mill test certificates as well as full quality-assurance documentation. Our name speaks to our roots: European-sourced materials that is backed by the certificates and rigor that buyers from Asia as well as the Gulf and Africa are looking for.
Each bar we deliver is accompanied by EN 10204 3.1 mill test certificates as well as complete documentation of quality, so what you receive corresponds to what’s written in the documents. We carry a selection of sizes and grades ready for transport, and cut length upon the request of customers, which results in quicker lead times, whether you’re ordering just a one-off spec or a complete project tonnage.
We operate an actual wholesale business that is that is supported with an internationally-operated supply chain therefore we are able to serve fabricators sourcing one grade the same way in the same way as an EPC contractor who is placing a large order. Our clients include manufacturers, fabricators EPC construction companies, engineers oil and gas projects as well as construction companies. we design our inventory as well as documentation to show what buyers need to bring projects forward.
Our customers trust us across Qatar, Oman, Bahrain, Kuwait, Jordan, Malaysia, Singapore, Thailand, Taiwan, Turkey, Italy and South Africa. If you’re looking to source an Gulf energy project, or a construction project within Southeast Asia, you get the same quality of certified material, the exact documentation, and the exact delivery procedure.
Frequently Asked Questions
When should I choose 20MnCr5 over 16MnCr5?
What is the difference between 20MnCr5 and 16MnCr5?
Which delivery condition should I order for 20MnCr5 bar?
Is 20MnCr5 equivalent to SAE 5120?
How is 20MnCr5 case hardened and machined?
What are the limits of 20MnCr5?
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