AISI 4140 Steel Round Bar Sheet Plate, JIS SCM440, DIN 1.7225

What is AISI 4140 Steel?

AISI 4140 alloy steel round bar sheet plate belongs to medium hardenability steel.AISI 4140 steel has high fatigue strength and low notch sensitivity. Low-temperature impact toughness is also very high, no obvious temper brittleness. AISI 4140 steel round bar is mainly used after quenching and tempering state. it is used to manufacture high-strength parts under impact loads and the fittings with large cross-sections and other stressed members. Such as the horizontal eccentric shaft of the horizontal forging machine, the crankshaft of the forging press, and etc.
Its equivalent grade is JIS SCM440 and DIN 1.7225. The properties and composition of 4140 steel round bar sheet plate as below.

AISI 4140 Steel Round Bar Sheet Plate Supply Range
Round BarDiameter: 8–3000mm;
Other specifications support customization.
Black, Peeled, Machined(Turned), Polished(Grounded)
Based on customer's needs.
Sheet/Plate/SlabThickness:10–1500mm; Width: 200–3000mm;
Length: Can be customized
Black, Peeled, Machined, Polished(Ground, Grinded, Milled)
Based on customer's needs.

4140 Steel Grade Equivalent Chart

Country USA Germany/UK/France JAPAN
Standard ASTM A29 / A29M-05 EN 10083/3-2006 JIS G4053-2008
Grades 4140 42CrMo4(1.7225) SCM440

4140 Steel Chemical Composition

STAND C(%) Mn(%) P(%) S(%) Si(%) Cr(%) Mo(%) Ni(%)
ASTM A29 / A29M-05 0.38-0.43 0.75-1.00 Max 0.035 Max 0.040 0.15-0.35 0.80-1.10 0.15-0.25 -
EN 10083/3-2006 0.38-0.45 0.60-0.90 Max 0.025 Max 0.035 Max 0.40 0.90-1.20 0.15-0.30 -
JIS G4053-2008 0.38-0.43 0.60-0.90 Max 0.030 Max 0.030 0.15-0.35 0.90-1.20 0.15-0.30 ≤0.25

4140 Steel Physical Properties

Properties Metric Imperial
Density 7.85 g/cm³ 0.284 lb/in³
Melting point 1416°C 2580°F

1.7225 Steel Mechanical Properties

Properties Metric Imperial
Tensile strength 655 MPa 95000 psi
Yield strength 415 MPa 60200 psi
Bulk modulus(typical for steel) 140 GPa 20300 ksi
Shear modulus(typical for steel) 80 GPa 11600 ksi
Elastic modulus 190-210 GPa 27557-30458 ksi
Poisson's ratio 0.27-0.30 0.27-0.30
Elongation at break(in 50 mm) 25.70% 25.70%
Hardness, Brinell 197 197
Hardness, Knoop(converted from Brinell hardness) 219 219
Hardness, Rockwell B(converted from Brinell hardness) 92 92
Hardness, Rockwell C(converted from Brinell hardness. Value below normal HRC range, for comparison purposes only) 13 13
Hardness, Vickers(converted from Brinell hardness) 207 207
Machinability(based on AISI 1212 as 100 machinability) 65 65

ASTM 4140 Steel Application

4140 steel is medium hardenability steel with good strength and good comprehensive mechanical properties after heat treatment. It has good manufacturability. The maximum temperature of use is 427 °C. It can be used to make turbine fastener, tool bodies, forming dies, brake dies and etc. And it also as the material of Oil deep well drill pipe joints and fishing tools below 2000m.


AISI 4140 Steel Characteristics

1.It is low alloy steel with chromium, molybdenum, and manganese.
2.Great toughness, fatigue strength, abrasion and impact resistance.
3.It is widely be used in the industry due to its excellent versatility and usefulness.
4.The higher carbon content in it, the higher the strength and heat treatment capabilities it is.
5.It can be oil hardened to relatively high hardenability.

4140 Steel Round Bar Sheet Plate Heat Treatment

At the annealed condition, 1.7225 alloy tool steel has good machinability.

DIN 1.7225 steel has high ductility. It can be formed using conventional techniques in the annealed condition. It is required more pressure or force for forming because it is tougher than plain carbon steels.

1.7225 alloy steel can be welded using all advanced techniques. But, the mechanical properties of it will be affected if it is welded in the heat treated condition, and post weld heat treatment should be performed.

Heat Treatment
1.7225 tool steel is heated at 845°C(1550°F) followed by quenching in oil. Before hardening, it can be normalized by heating at 913°C (1675°F) for a long period of time followed by air cooling.

It is forged at 926 to 1205°C(1700 to 2200°F)

Hot Working
4140 steel can be hot worked at 816 to 1038°C(1500 to 1900°F)

Cold Working
1.7225 steel can be cold worked using conventional methods in the annealed condition.

Heat it to 800℃ – 850℃, hold until temperature is uniform throughout the section and cool in furnace.

Heat 1.7225 alloy steel to 870℃ – 900℃, hold it until the temperature is uniform throughout the section, soak for 10 – 15 minutes and cool in still air.

DIN 1.7225 steel can be tempered at 205 to 649°C (400 to 1200°F) depending upon the desired hardness level. The hardness of the steel can be increased if it has lower tempering temperature. For example, tensile strength of 225 ksi cab be achieved by tempering at 316°C (600°F), and tensile strength of 130 ksi can be achieved by tempering at 538°C (1000°F).

DIN 1.7225 alloy steel can be hardened by cold working, or heating and quenching.


How is SAE 4140 steel tested?

Our AISI 4140 steel round bar and steel plate composition detection is carried out by a spectrometer, which is fast, accurate and efficient in detection; hardness is tested by a hardness tester,
The hardness tester is based on the Leeb hardness measurement principle, which can easily and quickly measure a variety of metal materials. While displaying the hardness measurement value immediately, it can be freely converted between different hardness scales, and the tolerance limit can be set in advance, and it will automatically alarm when it exceeds the range.
1. Measuring range: (170-960)HLD,(17-68.5)HRC,(19-651)HB,(80-976)HV,(30-100)HS,(59-85)HRA(13-100 )HRB
2. Measurement direction: support 360° (vertical down, oblique down, horizontal, oblique up, vertical up)
3. Hardness scale: Richter (HL), Brinell (HB), Rockwell B (HRB), Rockwell C (HRC), Rockwell A (HRA), Vickers (HV), Shore (HS)
4. Display: quarter dot matrix LCD
5. Data storage: maximum 500 groups (impact times 32 to 1)
6. Working voltage: 3V (2 AA size alkaline batteries connected in series)
7. Continuous working time: about 100 hours (when the backlight is not turned on)

We have been specializing in the production of 4140 alloy steel for decades, providing 4140/1.7225/SCM440 alloy round bar, square and flat steel, etc. We have our own cutting and processing facilities, rich production experience, and the specifications can be customized according to your needs Requires tailoring and customization. Over the years, we have been focusing on special steel dealers and suppliers with high-quality booths. As a professional AISI 4140 steel supplier, you are welcome to inquire at any time.

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