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41Cr4 / 1.7035 is a commonly used chromium alloy steel belonging to the European standard EN 10083-3 and EN 10250-3. It is widely applied in various industries, including automotive manufacturing, machinery construction, and general engineering. Due to its versatility, you can find its equivalent grades in different national standards, such as AISI 5140 from American standard ASTM A29/A29M, SCr440 from Japanese standard JIS G4105, 40Cr from Chinese standard GB/T 3077, 530M40 from British standard BS 970.
41Cr4 is part of the Cr steel series, with a carbon content of 0.38-0.45%. After quenching and tempering (QT), it achieves good strength, toughness, and wear resistance, making it suitable for high-stress components such as gears, shafts, and bolts. Its excellent hardenability and machinability also make it a preferred choice for heat-treated structural parts.
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AISI 5140 / DIN 41Cr4 (1.7035) / JIS SCr440 is a versatile medium-carbon chromium alloy steel engineered for quenching and tempering (QT) processes, renowned for its exceptional balance of strength, toughness, and machinability. Compliant with global standards—including ASTM A29 (U.S.), EN 10083-3 / EN 10250-3 (Europe), JIS G4105 (Japan), GB/T 3077 (China), and BS 970 (U.K.)—this alloy is a staple in industries requiring reliable performance under high mechanical stress.
A key advantage of this steel is its cross-standard compatibility, with direct equivalents that simplify global sourcing: AISI 5140 (U.S.), DIN 41Cr4 (1.7035) (Europe), JIS SCr440 (Japan), 40Cr (China), and 530M40 (U.K.). Its core chemical composition—featuring 0.38-0.45% carbon content and 0.7-1.2% chromium content (varies by grade)—enables optimal heat treatment response, resulting in a material that excels in both load-bearing and wear-resistant applications.
After quenching and tempering, AISI 5140 / DIN 41Cr4 1.7035 achieves a tensile strength range of 800-1200 MPa (depending on size) and a minimum yield strength of 560 MPa, paired with elongation values of 11-14% and impact resistance of 35 J (minimum at room temperature). These properties make it ideal for components that demand durability without sacrificing ductility, such as gears, shafts, and high-strength fasteners. Whether used in automotive transmissions, industrial machinery, or precision tooling, this alloy consistently meets the rigorous performance requirements of modern manufacturing.
The chemical makeup of AISI 5140 / DIN 41Cr4 1.7035 / JIS SCr440 is carefully calibrated to enhance its mechanical and thermal properties, with strict limits on impurities to ensure reliability. Below is a breakdown of key elements (by grade) and their roles:
Carbon (C): 0.38-0.45% (DIN 41Cr4) / 0.38-0.43% (AISI 5140/SCr440): The primary hardening element, carbon controls the steel’s strength and response to heat treatment. This range balances hardness and toughness, avoiding brittleness while enabling high tensile strength.
Chromium (Cr): 0.9-1.2% (DIN 41Cr4/SCr440) / 0.7-0.9% (AISI 5140): Improves hardenability, corrosion resistance, and wear resistance—critical for components exposed to friction or harsh environments.
Manganese (Mn): 0.60-0.90% (DIN 41Cr4) / 0.70-0.90% (AISI 5140): Enhances ductility and toughness, while also refining the steel’s microstructure during forging and heat treatment.
Silicon (Si): ≤0.40% (DIN 41Cr4) / 0.15-0.35% (AISI 5140/SCr440): Boosts oxidation resistance and strengthens the steel at elevated temperatures, supporting long-term performance in high-heat applications.
Phosphorus (P) & Sulfur (S): ≤0.035% (maximum) : Strictly limited to minimize brittleness and improve machinability, ensuring the steel can be precision-machined into complex components without cracking.
This composition not only optimizes the alloy’s QT performance but also ensures consistency across batches, a critical factor for industries like automotive and aerospace where part interchangeability is essential.
The mechanical performance of AISI 5140 / DIN 41Cr4 1.7035 is tailored to withstand high stress, with properties that vary slightly by component size (per EN 10083-3 standards) to meet application-specific needs:
For small sizes (d≤16mm / t≤8mm): Tensile strength of 1000-1200 MPa, minimum yield strength of 800 MPa, elongation of 11% (minimum), and reduction of area of 30% (minimum).
For medium sizes (16＜d≤40mm / 8＜t≤20mm): Tensile strength of 900-1100 MPa, minimum yield strength of 660 MPa, elongation of 12% (minimum), and reduction of area of 35% (minimum).
For large sizes (40＜d≤100mm / 20＜t≤60mm): Tensile strength of 800-950 MPa, minimum yield strength of 560 MPa, elongation of 14% (minimum), and reduction of area of 40% (minimum).
For open-die forgings (per EN 10250-3), DIN 41Cr4 maintains a minimum tensile strength of 800 MPa and minimum yield strength of 560 MPa for sizes up to 70mm, with elongation of 14% (minimum) and impact resistance of 35 J (minimum at room temperature). These properties make it suitable for heavy-duty components like crane shafts and industrial gearboxes.
AISI 5140 / DIN 41Cr4 1.7035 exhibits excellent hardenability, a key attribute for components requiring uniform hardness across thick sections. Its hardenability is classified into three grades (+H, +HH, +HL) based on Rockwell C (HRC) hardness at varying distances from the quenched end:
+H Grade: At 1.5mm from the quenched end, hardness ranges from 53-61 HRC; at 50mm, it decreases to 35-36 HRC (minimum of 35 HRC).
+HH Grade (high hardenability): At 1.5mm, hardness ranges from 56-61 HRC; at 50mm, it remains at 24-36 HRC (minimum of 24 HRC), ideal for thicker components.
+HL Grade (low hardenability): At 1.5mm, hardness ranges from 53-58 HRC; at 50mm, it drops to 29-30 HRC (minimum of 29 HRC).
Surface hardness can be further enhanced via specialized treatments:
Flame or induction hardening: Achieves a surface hardness of 53 HRC, perfect for wear-prone components like bearing rings.
Soft annealing (+A): Reduces hardness to ≤241 HB for easier machining of complex parts.
Shearability improvement (+S): Limits hardness to ≤255 HB to optimize cutting and forming processes.
Quenching and tempering (+QT): The most common treatment, delivering a hardness range of 28-32 HRC—a sweet spot for balance between strength and machinability.
To accommodate diverse manufacturing needs, JIS SCr440 / AISI 5140 is available in multiple forms with precise size tolerances:
Cold-drawn bars: Diameter range of Φ3-80mm, length of 6000-9000mm, with a surface finish tolerance of +0/+0.1mm (peeled) or +0/+0.05mm (ground/polished) and maximum straightness of 1mm/1000mm.
Hot-rolled bars: Diameter range of Φ18-300mm, length of 6000-9000mm, tolerance of +0/+1mm (black rolled) and maximum straightness of 3mm/1000mm.
Hot-forged bars: Diameter range of Φ100-1200mm, length of 3000-5800mm, tolerance of +0/+5mm (black forged). Custom forgings are available with a minimum order quantity (MOQ) of 1 piece.
Hot-rolled plates/sheets: Thickness of 3-200mm, width of 1500-2500mm, length of 2000-5800mm, with tolerance matching hot-rolled bars.
Hunan Qilu Steel maintains monthly stocks of hot-rolled and cold-drawn bars (over 10,000 tons) in popular diameters (e.g., 18mm, 24mm, 50mm, 72mm, 100mm, 200mm), ensuring fast delivery for urgent orders.
To unlock the full potential of AISI 5140 / DIN 41Cr4 1.7035, recommended heat treatment and forging processes are critical:
Soft annealing: Heat to 670-710℃, soak at temperature, then furnace-cool. This reduces internal stress and lowers hardness for machining.
Normalization: Heat to 850-880℃, soak, then air-cool. Refines the microstructure, improving uniformity for subsequent QT treatment.
Quenching and tempering: Heat to 820-860℃ (lower end for water quenching, upper end for oil quenching), soak, quench in water or oil, then temper at 540-680℃ and air-cool. This process develops the alloy’s signature strength-toughness balance.
Forging: Heat ingots to 1150-1200℃, forge at a minimum temperature of 800-850℃, then sand-cool to prevent cracking. Forged components benefit from grain refinement, enhancing overall durability.
While AISI 5140 / DIN 41Cr4 1.7035 offers exceptional performance, its weldability is classified as moderate to poor due to its carbon content (0.38-0.45%)—exceeding the 0.25% threshold where weldability begins to deteriorate. To minimize cracking during welding:
Preheat the base material to 200-300℃ before welding.
Use low-hydrogen electrodes (e.g., E7018) to reduce hydrogen-induced cracking.
Maintain interpass temperatures above 200℃ during multi-pass welding.
Post-weld heat treatment (PWHT) at 600-650℃ to relieve residual stress.
These steps ensure welded joints retain sufficient strength for non-critical applications; for high-stress components, mechanical fastening (e.g., bolts) is preferred over welding.
The automotive sector relies heavily on AISI 5140 / DIN 41Cr4 1.7035 for components that endure constant stress, vibration, and wear. Key applications include:
Transmission systems: Gears, drive shafts, and camshafts—benefiting from the alloy’s 1000-1200 MPa tensile strength and wear resistance (53 HRC via induction hardening).
Chassis and suspension: Steering knuckles, steering shafts, and suspension arms—leveraging the alloy’s toughness (35 J impact resistance) to withstand road shocks.
Engine and powertrain: Cylinder piston rods, hydraulic valve cores, and connecting rods—where the QT-induced 28-32 HRC hardness balances strength and machinability for precision fitting.
Major automakers specify this alloy for its consistency, ensuring parts meet strict safety and performance standards.
In mechanical engineering, JIS SCr440 / AISI 5140 is a top choice for high-load components in industrial machinery:
Power transmission: Gearboxes, differential parts, and torque converters—relying on the alloy’s uniform hardenability to maintain strength across thick sections.
Fasteners and structural parts: High-strength bolts, flanges, and brackets—benefiting from the alloy’s ≥560 MPa yield strength to resist loosening under heavy loads.
Hydraulic and pneumatic systems: Hydraulic cylinder rods and valve spools—where the alloy’s machinability (≤241 HB after soft annealing) enables tight tolerances and smooth surfaces.
It is commonly used in manufacturing equipment, construction machinery (e.g., excavator arms), and mining gear (e.g., conveyor shafts) due to its durability in harsh operating conditions.
AISI 5140 / DIN 41Cr4 1.7035 is a cost-effective solution for mold and tooling applications that require moderate hardness and machinability:
Mold bases and fixtures: Jigs, fixtures, and tooling substrates—where the alloy’s soft annealing hardness (≤241 HB) allows easy machining of complex shapes, and subsequent QT treatment (28-32 HRC) provides long-term dimensional stability.
Auxiliary mold components: Ejector pins and guide pillars—benefiting from the alloy’s wear resistance to withstand repeated cycles in injection molding or stamping processes.
Compared to high-carbon tool steels, it offers a lower cost point for non-cutting tool applications while still meeting performance needs.
Agricultural and industrial equipment demand materials that resist abrasion and impact, making JIS SCr440 / DIN 41Cr4 1.7035 an ideal choice:
Agricultural machinery: Harvester knives, thresher shafts, and transmission chains—leveraging the alloy’s 53 HRC surface hardness (flame-hardened) to resist wear from crop residue and soil.
Industrial wear components: Bearing rings, rolling elements, and conveyor rollers—where the alloy’s combination of hardness (28-32 HRC) and toughness (35 J impact) prevents premature failure.
Mining and construction: Crusher parts and screen shafts—benefiting from the alloy’s forging capability (up to Φ1200mm) to create large, durable components for heavy-duty operations.
AISI 5140 / DIN 41Cr4 1.7035 has direct equivalents across global standards to simplify sourcing:
U.S.: AISI 5140 (per ASTM A29/A29M)
Europe: DIN 41Cr4 (1.7035) (per EN 10083-3 / EN 10250-3)
Japan: JIS SCr440 (per JIS G4105)
China: 40Cr (per GB/T 3077)
U.K.: 530M40 (per BS 970)
These equivalents share similar chemical compositions and mechanical properties, ensuring interchangeability in most applications.
After standard quenching and tempering (+QT), DIN 41Cr4 1.7035 achieves a hardness range of 28-32 HRC—the most common specification for balancing strength and machinability. For specialized needs:
Soft annealing (+A) reduces hardness to ≤241 HB (ideal for machining).
Flame or induction hardening boosts surface hardness to 53 HRC (for wear-prone parts).
Shearability treatment (+S) limits hardness to ≤255 HB (for cutting/forming).
Hardness also varies by hardenability grade (+H, +HH, +HL) and component size, as outlined in EN 10083-3.
JIS SCr440 is supplied in multiple forms to suit diverse manufacturing needs:
Cold-drawn bars: Φ3-80mm (length: 6000-9000mm)
Hot-rolled bars: Φ18-300mm (length: 6000-9000mm)
Hot-forged bars: Φ100-1200mm (length: 3000-5800mm; custom sizes available)
Hot-rolled plates/sheets: 3-200mm thick, 1500-2500mm wide, 2000-5800mm long
Hunan Qilu Steel stocks hot-rolled and cold-drawn bars in popular diameters (e.g., 18mm, 24mm, 50mm, 100mm) for immediate delivery; custom forgings have a lead time of 15 days with an MOQ of 1 piece.
The chemical composition of AISI 5140 is tailored to optimize its properties:
Carbon (0.38-0.43%): Enables high hardness after QT and controls strength.
Chromium (0.7-0.9%): Improves hardenability and wear resistance, critical for gears and shafts.
Manganese (0.70-0.90%): Enhances toughness and refines microstructure, reducing brittleness.
Silicon (0.15-0.35%): Boosts oxidation resistance, supporting performance in high-heat environments.
Low P/S (≤0.035%): Minimizes impurities, improving machinability and preventing cracking.
This balance ensures AISI 5140 performs reliably in high-stress applications while remaining easy to process.
Recommended heat treatment for DIN 41Cr4 1.7035 depends on the desired outcome:
Soft annealing: 670-710℃ (soak) → furnace-cool. For machining.
Normalization: 850-880℃ (soak) → air-cool. For microstructure refinement.
Quenching and tempering: 820-860℃ (soak) → quench (water/oil) → temper at 540-680℃ (air-cool). For strength-toughness balance.
Flame/induction hardening: Heat surface to 850-900℃ → quench. For localized wear resistance (53 HRC).
Always follow EN 10083-3 guidelines for temperature soak times (based on component size) to ensure uniform results.
1: Steel equivalent
Country | USA | Europe | China | British | Japan |
Standard | ASTM A29 | EN10083-3 | GB/T3077 | BS970 | JIS G4104 |
Grade | 5140 | 41Cr4/1.7035 | 40Cr | 530M40 | SCr440 |
2: Chemical composition
Grade | C | Si | Mn | P | S | Cr |
5140 | 0.38-0.43 | 0.15-0.35 | 0.70-0.90 | 0.035Max | 0.040Max | 0.7-0.9 |
41Cr4/1.7035 | 0.38-0.45 | 0.4Max | 0.60-0.90 | 0.035Max | 0.035Max | 0.9-1.2 |
40Cr | 0.37-0.44 | 0.17-0.37 | 0.50-0.80 | 0.030Max | 0.030Max | 0.8-1.1 |
530M40 | 0.36-0.44 | 0.10-0.40 | 0.60-0.90 | 0.035Max | 0.040Max | 0.9-1.2 |
SCr440 | 0.38-0.43 | 0.15-0.35 | 0.60-0.85 | 0.030Max | 0.030Max | 0.9-1.2 |
3: Mechanical properties .
Mechanical properties for 41Cr4 quenching and tempering alloy steel according to EN10083-3.
Size range | Tensile strength | Yield strength | Alongation | Area of reduction | Impact value At RT/J |
d≤16 t≤8 | 1000-1200Mpa | 800Mpa Min | 11% Min | 30% Min | / |
16＜d≤40 8＜t≤20 | 900-1100Mpa | 660Mpa Min | 12% Min | 35%Min | 35J Min |
40＜d≤100 20＜t≤60 | 800-950Mpa | 560Mpa Min | 14% Min | 40%Min | 35J Min |
Sampling and preparation of test pieces for 41Cr4 quenching and tempering steel.
1): According to EN10083-1, all samples shall be taken at a distance of 12.5mm below the heat treated surface
2): As stipulated in the contract between buyer and seller.
Mechanical properties for 41Cr4 open die forgings steel according to EN10250-3
Size range | Tensile strength | Yield strength | Alongation | Impact value at RT/J | ||
14% Min | 35J Min | |||||
d≤70 | 800Mpa Min | 560Mpa Min | ||||
Sampling and preparation of test pieces for steel forging.
1: According to EN10250-1, all samples shall be taken at a distance of 4/T below the heat treated surface (with a minimum of 20mm and a maximum of 80mm), and t/2 from the end (where t is the equivalent thickness of the thickness of the ruling section of the forging at the time of heat treatment.
2: As stipulated in the contract between buyer and seller.
4: Surface hardness and hardenability.
Heat Treatment | Hardness |
Flame or Induction hardening | 53HRC |
Treated to improve shearability (+S) | HB255Max |
Soft annealed (+A) | HB241Max |
Quenched and tempred (+QT) | HRC28-32(Common Range) |
Where the steel is ordered by using the symbols for normal (+H) or restricted (+HL, +HH) hardenability requirements, the hardenability values should apply below:
Distance in mm from quenched end | ||||||||||||||||
Distance | 1.5 | 3 | 5 | 7 | 9 | 11 | 13 | 15 | 20 | 25 | 30 | 35 | 40 | 45 | 50 | |
Hardness In HRC + H | max | 61 | 61 | 60 | 59 | 58 | 56 | 54 | 52 | 46 | 42 | 40 | 38 | 37 | 36 | 35 |
min | 53 | 52 | 50 | 47 | 41 | 37 | 34 | 32 | 29 | 26 | 23 | 21 | / | / | / | |
Hardness In HRC + HH | max | 61 | 61 | 60 | 59 | 58 | 56 | 54 | 52 | 46 | 42 | 40 | 38 | 37 | 36 | 35 |
min | 56 | 55 | 53 | 51 | 47 | 43 | 41 | 39 | 35 | 31 | 29 | 27 | 26 | 25 | 24 | |
Hardness In HRC + HL | max | 58 | 58 | 57 | 55 | 52 | 50 | 47 | 45 | 40 | 37 | 34 | 32 | 31 | 30 | 29 |
min | 53 | 52 | 50 | 47 | 41 | 37 | 34 | 32 | 29 | 26 | 23 | 21 | / | / | / | |
Scatter bands for the Rockwell - C hardness in the end quench hardenability test.
5: Supply size & Tolerance & Stock size
Product type | Size range | Length |
Cold drawn bar | Φ3-Φ80mm | 6000-9000mm |
Hot rolled bar | Φ18-Φ300mm | 6000-9000mm |
Hot forged bar | Φ100-Φ1200mm | 3000-5800mm |
Hot rolled plate/sheet | T:3-200mm; W:1500-2500mm | 2000-5800mm |
Hot Forged block | T: 80-800mm; W: 100-2500mm | 2000-5800mm |
Surface Finish | Turned | Milled | Grinding(Best) | Polished(Best) | Peeled(Best) | Black Forged | Black Rolled |
Tolerance | +0/+3mm | +0/+3mm | +0/+0.05mm | +0/+0.05mm | +0/+0.1mm | +0/+5mm | +0/+1mm |
Straighness | 1mm/1000mm max. | 3mm/1000mm max. | |||||
Qilu steel stock hot rolled bar and forged bars more than ten thousands tons every month, below our our stock size.
18 | 20 | 22 | 24 | 25 | 28 | 30 | 32 | 35 | 36 | 38 | 40 | 42 | 48 | 48 |
50 | 52 | 55 | 60 | 65 | 70 | 72 | 75 | 80 | 85 | 90 | 95 | 100 | 105 | 110 |
115 | 120 | 125 | 130 | 140 | 150 | 160 | 170 | 180 | 190 | 200 | 210 | 220 | 230 | 240 |
250 | 260 | 270 | 280 | 290 | 300 |
AISI 5140 / DIN 41Cr4 (1.7035) / JIS SCr440 is a versatile medium-carbon chromium alloy steel engineered for quenching and tempering (QT) processes, renowned for its exceptional balance of strength, toughness, and machinability. Compliant with global standards—including ASTM A29 (U.S.), EN 10083-3 / EN 10250-3 (Europe), JIS G4105 (Japan), GB/T 3077 (China), and BS 970 (U.K.)—this alloy is a staple in industries requiring reliable performance under high mechanical stress.
A key advantage of this steel is its cross-standard compatibility, with direct equivalents that simplify global sourcing: AISI 5140 (U.S.), DIN 41Cr4 (1.7035) (Europe), JIS SCr440 (Japan), 40Cr (China), and 530M40 (U.K.). Its core chemical composition—featuring 0.38-0.45% carbon content and 0.7-1.2% chromium content (varies by grade)—enables optimal heat treatment response, resulting in a material that excels in both load-bearing and wear-resistant applications.
After quenching and tempering, AISI 5140 / DIN 41Cr4 1.7035 achieves a tensile strength range of 800-1200 MPa (depending on size) and a minimum yield strength of 560 MPa, paired with elongation values of 11-14% and impact resistance of 35 J (minimum at room temperature). These properties make it ideal for components that demand durability without sacrificing ductility, such as gears, shafts, and high-strength fasteners. Whether used in automotive transmissions, industrial machinery, or precision tooling, this alloy consistently meets the rigorous performance requirements of modern manufacturing.
The chemical makeup of AISI 5140 / DIN 41Cr4 1.7035 / JIS SCr440 is carefully calibrated to enhance its mechanical and thermal properties, with strict limits on impurities to ensure reliability. Below is a breakdown of key elements (by grade) and their roles:
Carbon (C): 0.38-0.45% (DIN 41Cr4) / 0.38-0.43% (AISI 5140/SCr440): The primary hardening element, carbon controls the steel’s strength and response to heat treatment. This range balances hardness and toughness, avoiding brittleness while enabling high tensile strength.
Chromium (Cr): 0.9-1.2% (DIN 41Cr4/SCr440) / 0.7-0.9% (AISI 5140): Improves hardenability, corrosion resistance, and wear resistance—critical for components exposed to friction or harsh environments.
Manganese (Mn): 0.60-0.90% (DIN 41Cr4) / 0.70-0.90% (AISI 5140): Enhances ductility and toughness, while also refining the steel’s microstructure during forging and heat treatment.
Silicon (Si): ≤0.40% (DIN 41Cr4) / 0.15-0.35% (AISI 5140/SCr440): Boosts oxidation resistance and strengthens the steel at elevated temperatures, supporting long-term performance in high-heat applications.
Phosphorus (P) & Sulfur (S): ≤0.035% (maximum) : Strictly limited to minimize brittleness and improve machinability, ensuring the steel can be precision-machined into complex components without cracking.
This composition not only optimizes the alloy’s QT performance but also ensures consistency across batches, a critical factor for industries like automotive and aerospace where part interchangeability is essential.
The mechanical performance of AISI 5140 / DIN 41Cr4 1.7035 is tailored to withstand high stress, with properties that vary slightly by component size (per EN 10083-3 standards) to meet application-specific needs:
For small sizes (d≤16mm / t≤8mm): Tensile strength of 1000-1200 MPa, minimum yield strength of 800 MPa, elongation of 11% (minimum), and reduction of area of 30% (minimum).
For medium sizes (16＜d≤40mm / 8＜t≤20mm): Tensile strength of 900-1100 MPa, minimum yield strength of 660 MPa, elongation of 12% (minimum), and reduction of area of 35% (minimum).
For large sizes (40＜d≤100mm / 20＜t≤60mm): Tensile strength of 800-950 MPa, minimum yield strength of 560 MPa, elongation of 14% (minimum), and reduction of area of 40% (minimum).
For open-die forgings (per EN 10250-3), DIN 41Cr4 maintains a minimum tensile strength of 800 MPa and minimum yield strength of 560 MPa for sizes up to 70mm, with elongation of 14% (minimum) and impact resistance of 35 J (minimum at room temperature). These properties make it suitable for heavy-duty components like crane shafts and industrial gearboxes.
AISI 5140 / DIN 41Cr4 1.7035 exhibits excellent hardenability, a key attribute for components requiring uniform hardness across thick sections. Its hardenability is classified into three grades (+H, +HH, +HL) based on Rockwell C (HRC) hardness at varying distances from the quenched end:
+H Grade: At 1.5mm from the quenched end, hardness ranges from 53-61 HRC; at 50mm, it decreases to 35-36 HRC (minimum of 35 HRC).
+HH Grade (high hardenability): At 1.5mm, hardness ranges from 56-61 HRC; at 50mm, it remains at 24-36 HRC (minimum of 24 HRC), ideal for thicker components.
+HL Grade (low hardenability): At 1.5mm, hardness ranges from 53-58 HRC; at 50mm, it drops to 29-30 HRC (minimum of 29 HRC).
Surface hardness can be further enhanced via specialized treatments:
Flame or induction hardening: Achieves a surface hardness of 53 HRC, perfect for wear-prone components like bearing rings.
Soft annealing (+A): Reduces hardness to ≤241 HB for easier machining of complex parts.
Shearability improvement (+S): Limits hardness to ≤255 HB to optimize cutting and forming processes.
Quenching and tempering (+QT): The most common treatment, delivering a hardness range of 28-32 HRC—a sweet spot for balance between strength and machinability.
To accommodate diverse manufacturing needs, JIS SCr440 / AISI 5140 is available in multiple forms with precise size tolerances:
Cold-drawn bars: Diameter range of Φ3-80mm, length of 6000-9000mm, with a surface finish tolerance of +0/+0.1mm (peeled) or +0/+0.05mm (ground/polished) and maximum straightness of 1mm/1000mm.
Hot-rolled bars: Diameter range of Φ18-300mm, length of 6000-9000mm, tolerance of +0/+1mm (black rolled) and maximum straightness of 3mm/1000mm.
Hot-forged bars: Diameter range of Φ100-1200mm, length of 3000-5800mm, tolerance of +0/+5mm (black forged). Custom forgings are available with a minimum order quantity (MOQ) of 1 piece.
Hot-rolled plates/sheets: Thickness of 3-200mm, width of 1500-2500mm, length of 2000-5800mm, with tolerance matching hot-rolled bars.
Hunan Qilu Steel maintains monthly stocks of hot-rolled and cold-drawn bars (over 10,000 tons) in popular diameters (e.g., 18mm, 24mm, 50mm, 72mm, 100mm, 200mm), ensuring fast delivery for urgent orders.
To unlock the full potential of AISI 5140 / DIN 41Cr4 1.7035, recommended heat treatment and forging processes are critical:
Soft annealing: Heat to 670-710℃, soak at temperature, then furnace-cool. This reduces internal stress and lowers hardness for machining.
Normalization: Heat to 850-880℃, soak, then air-cool. Refines the microstructure, improving uniformity for subsequent QT treatment.
Quenching and tempering: Heat to 820-860℃ (lower end for water quenching, upper end for oil quenching), soak, quench in water or oil, then temper at 540-680℃ and air-cool. This process develops the alloy’s signature strength-toughness balance.
Forging: Heat ingots to 1150-1200℃, forge at a minimum temperature of 800-850℃, then sand-cool to prevent cracking. Forged components benefit from grain refinement, enhancing overall durability.
While AISI 5140 / DIN 41Cr4 1.7035 offers exceptional performance, its weldability is classified as moderate to poor due to its carbon content (0.38-0.45%)—exceeding the 0.25% threshold where weldability begins to deteriorate. To minimize cracking during welding:
Preheat the base material to 200-300℃ before welding.
Use low-hydrogen electrodes (e.g., E7018) to reduce hydrogen-induced cracking.
Maintain interpass temperatures above 200℃ during multi-pass welding.
Post-weld heat treatment (PWHT) at 600-650℃ to relieve residual stress.
These steps ensure welded joints retain sufficient strength for non-critical applications; for high-stress components, mechanical fastening (e.g., bolts) is preferred over welding.
The automotive sector relies heavily on AISI 5140 / DIN 41Cr4 1.7035 for components that endure constant stress, vibration, and wear. Key applications include:
Transmission systems: Gears, drive shafts, and camshafts—benefiting from the alloy’s 1000-1200 MPa tensile strength and wear resistance (53 HRC via induction hardening).
Chassis and suspension: Steering knuckles, steering shafts, and suspension arms—leveraging the alloy’s toughness (35 J impact resistance) to withstand road shocks.
Engine and powertrain: Cylinder piston rods, hydraulic valve cores, and connecting rods—where the QT-induced 28-32 HRC hardness balances strength and machinability for precision fitting.
Major automakers specify this alloy for its consistency, ensuring parts meet strict safety and performance standards.
In mechanical engineering, JIS SCr440 / AISI 5140 is a top choice for high-load components in industrial machinery:
Power transmission: Gearboxes, differential parts, and torque converters—relying on the alloy’s uniform hardenability to maintain strength across thick sections.
Fasteners and structural parts: High-strength bolts, flanges, and brackets—benefiting from the alloy’s ≥560 MPa yield strength to resist loosening under heavy loads.
Hydraulic and pneumatic systems: Hydraulic cylinder rods and valve spools—where the alloy’s machinability (≤241 HB after soft annealing) enables tight tolerances and smooth surfaces.
It is commonly used in manufacturing equipment, construction machinery (e.g., excavator arms), and mining gear (e.g., conveyor shafts) due to its durability in harsh operating conditions.
AISI 5140 / DIN 41Cr4 1.7035 is a cost-effective solution for mold and tooling applications that require moderate hardness and machinability:
Mold bases and fixtures: Jigs, fixtures, and tooling substrates—where the alloy’s soft annealing hardness (≤241 HB) allows easy machining of complex shapes, and subsequent QT treatment (28-32 HRC) provides long-term dimensional stability.
Auxiliary mold components: Ejector pins and guide pillars—benefiting from the alloy’s wear resistance to withstand repeated cycles in injection molding or stamping processes.
Compared to high-carbon tool steels, it offers a lower cost point for non-cutting tool applications while still meeting performance needs.
Agricultural and industrial equipment demand materials that resist abrasion and impact, making JIS SCr440 / DIN 41Cr4 1.7035 an ideal choice:
Agricultural machinery: Harvester knives, thresher shafts, and transmission chains—leveraging the alloy’s 53 HRC surface hardness (flame-hardened) to resist wear from crop residue and soil.
Industrial wear components: Bearing rings, rolling elements, and conveyor rollers—where the alloy’s combination of hardness (28-32 HRC) and toughness (35 J impact) prevents premature failure.
Mining and construction: Crusher parts and screen shafts—benefiting from the alloy’s forging capability (up to Φ1200mm) to create large, durable components for heavy-duty operations.
AISI 5140 / DIN 41Cr4 1.7035 has direct equivalents across global standards to simplify sourcing:
U.S.: AISI 5140 (per ASTM A29/A29M)
Europe: DIN 41Cr4 (1.7035) (per EN 10083-3 / EN 10250-3)
Japan: JIS SCr440 (per JIS G4105)
China: 40Cr (per GB/T 3077)
U.K.: 530M40 (per BS 970)
These equivalents share similar chemical compositions and mechanical properties, ensuring interchangeability in most applications.
After standard quenching and tempering (+QT), DIN 41Cr4 1.7035 achieves a hardness range of 28-32 HRC—the most common specification for balancing strength and machinability. For specialized needs:
Soft annealing (+A) reduces hardness to ≤241 HB (ideal for machining).
Flame or induction hardening boosts surface hardness to 53 HRC (for wear-prone parts).
Shearability treatment (+S) limits hardness to ≤255 HB (for cutting/forming).
Hardness also varies by hardenability grade (+H, +HH, +HL) and component size, as outlined in EN 10083-3.
JIS SCr440 is supplied in multiple forms to suit diverse manufacturing needs:
Cold-drawn bars: Φ3-80mm (length: 6000-9000mm)
Hot-rolled bars: Φ18-300mm (length: 6000-9000mm)
Hot-forged bars: Φ100-1200mm (length: 3000-5800mm; custom sizes available)
Hot-rolled plates/sheets: 3-200mm thick, 1500-2500mm wide, 2000-5800mm long
Hunan Qilu Steel stocks hot-rolled and cold-drawn bars in popular diameters (e.g., 18mm, 24mm, 50mm, 100mm) for immediate delivery; custom forgings have a lead time of 15 days with an MOQ of 1 piece.
The chemical composition of AISI 5140 is tailored to optimize its properties:
Carbon (0.38-0.43%): Enables high hardness after QT and controls strength.
Chromium (0.7-0.9%): Improves hardenability and wear resistance, critical for gears and shafts.
Manganese (0.70-0.90%): Enhances toughness and refines microstructure, reducing brittleness.
Silicon (0.15-0.35%): Boosts oxidation resistance, supporting performance in high-heat environments.
Low P/S (≤0.035%): Minimizes impurities, improving machinability and preventing cracking.
This balance ensures AISI 5140 performs reliably in high-stress applications while remaining easy to process.
Recommended heat treatment for DIN 41Cr4 1.7035 depends on the desired outcome:
Soft annealing: 670-710℃ (soak) → furnace-cool. For machining.
Normalization: 850-880℃ (soak) → air-cool. For microstructure refinement.
Quenching and tempering: 820-860℃ (soak) → quench (water/oil) → temper at 540-680℃ (air-cool). For strength-toughness balance.
Flame/induction hardening: Heat surface to 850-900℃ → quench. For localized wear resistance (53 HRC).
Always follow EN 10083-3 guidelines for temperature soak times (based on component size) to ensure uniform results.
1: Steel equivalent
Country | USA | Europe | China | British | Japan |
Standard | ASTM A29 | EN10083-3 | GB/T3077 | BS970 | JIS G4104 |
Grade | 5140 | 41Cr4/1.7035 | 40Cr | 530M40 | SCr440 |
2: Chemical composition
Grade | C | Si | Mn | P | S | Cr |
5140 | 0.38-0.43 | 0.15-0.35 | 0.70-0.90 | 0.035Max | 0.040Max | 0.7-0.9 |
41Cr4/1.7035 | 0.38-0.45 | 0.4Max | 0.60-0.90 | 0.035Max | 0.035Max | 0.9-1.2 |
40Cr | 0.37-0.44 | 0.17-0.37 | 0.50-0.80 | 0.030Max | 0.030Max | 0.8-1.1 |
530M40 | 0.36-0.44 | 0.10-0.40 | 0.60-0.90 | 0.035Max | 0.040Max | 0.9-1.2 |
SCr440 | 0.38-0.43 | 0.15-0.35 | 0.60-0.85 | 0.030Max | 0.030Max | 0.9-1.2 |
3: Mechanical properties .
Mechanical properties for 41Cr4 quenching and tempering alloy steel according to EN10083-3.
Size range | Tensile strength | Yield strength | Alongation | Area of reduction | Impact value At RT/J |
d≤16 t≤8 | 1000-1200Mpa | 800Mpa Min | 11% Min | 30% Min | / |
16＜d≤40 8＜t≤20 | 900-1100Mpa | 660Mpa Min | 12% Min | 35%Min | 35J Min |
40＜d≤100 20＜t≤60 | 800-950Mpa | 560Mpa Min | 14% Min | 40%Min | 35J Min |
Sampling and preparation of test pieces for 41Cr4 quenching and tempering steel.
1): According to EN10083-1, all samples shall be taken at a distance of 12.5mm below the heat treated surface
2): As stipulated in the contract between buyer and seller.
Mechanical properties for 41Cr4 open die forgings steel according to EN10250-3
Size range | Tensile strength | Yield strength | Alongation | Impact value at RT/J | ||
14% Min | 35J Min | |||||
d≤70 | 800Mpa Min | 560Mpa Min | ||||
Sampling and preparation of test pieces for steel forging.
1: According to EN10250-1, all samples shall be taken at a distance of 4/T below the heat treated surface (with a minimum of 20mm and a maximum of 80mm), and t/2 from the end (where t is the equivalent thickness of the thickness of the ruling section of the forging at the time of heat treatment.
2: As stipulated in the contract between buyer and seller.
4: Surface hardness and hardenability.
Heat Treatment | Hardness |
Flame or Induction hardening | 53HRC |
Treated to improve shearability (+S) | HB255Max |
Soft annealed (+A) | HB241Max |
Quenched and tempred (+QT) | HRC28-32(Common Range) |
Where the steel is ordered by using the symbols for normal (+H) or restricted (+HL, +HH) hardenability requirements, the hardenability values should apply below:
Distance in mm from quenched end | ||||||||||||||||
Distance | 1.5 | 3 | 5 | 7 | 9 | 11 | 13 | 15 | 20 | 25 | 30 | 35 | 40 | 45 | 50 | |
Hardness In HRC + H | max | 61 | 61 | 60 | 59 | 58 | 56 | 54 | 52 | 46 | 42 | 40 | 38 | 37 | 36 | 35 |
min | 53 | 52 | 50 | 47 | 41 | 37 | 34 | 32 | 29 | 26 | 23 | 21 | / | / | / | |
Hardness In HRC + HH | max | 61 | 61 | 60 | 59 | 58 | 56 | 54 | 52 | 46 | 42 | 40 | 38 | 37 | 36 | 35 |
min | 56 | 55 | 53 | 51 | 47 | 43 | 41 | 39 | 35 | 31 | 29 | 27 | 26 | 25 | 24 | |
Hardness In HRC + HL | max | 58 | 58 | 57 | 55 | 52 | 50 | 47 | 45 | 40 | 37 | 34 | 32 | 31 | 30 | 29 |
min | 53 | 52 | 50 | 47 | 41 | 37 | 34 | 32 | 29 | 26 | 23 | 21 | / | / | / | |
Scatter bands for the Rockwell - C hardness in the end quench hardenability test.
5: Supply size & Tolerance & Stock size
Product type | Size range | Length |
Cold drawn bar | Φ3-Φ80mm | 6000-9000mm |
Hot rolled bar | Φ18-Φ300mm | 6000-9000mm |
Hot forged bar | Φ100-Φ1200mm | 3000-5800mm |
Hot rolled plate/sheet | T:3-200mm; W:1500-2500mm | 2000-5800mm |
Hot Forged block | T: 80-800mm; W: 100-2500mm | 2000-5800mm |
Surface Finish | Turned | Milled | Grinding(Best) | Polished(Best) | Peeled(Best) | Black Forged | Black Rolled |
Tolerance | +0/+3mm | +0/+3mm | +0/+0.05mm | +0/+0.05mm | +0/+0.1mm | +0/+5mm | +0/+1mm |
Straighness | 1mm/1000mm max. | 3mm/1000mm max. | |||||
Qilu steel stock hot rolled bar and forged bars more than ten thousands tons every month, below our our stock size.
18 | 20 | 22 | 24 | 25 | 28 | 30 | 32 | 35 | 36 | 38 | 40 | 42 | 48 | 48 |
50 | 52 | 55 | 60 | 65 | 70 | 72 | 75 | 80 | 85 | 90 | 95 | 100 | 105 | 110 |
115 | 120 | 125 | 130 | 140 | 150 | 160 | 170 | 180 | 190 | 200 | 210 | 220 | 230 | 240 |
250 | 260 | 270 | 280 | 290 | 300 |
