4340 Steel Forgings
Our 4340 alloy steel forgings have high strength, high toughness, good machinability, and good corrosion resistance. 4340 forged steel parts have excellent overall performance and are widely used in heavy machinery, aerospace, automotive, energy, shipbuilding, and general machinery industries.
- Customer drawings
- Heat treatment
- Inspection reports
Custom Materials · Heat Treatment · Machining
Built around the
drawing.
Controlled through
delivery.
Every 4340 steel forgings begins with a technical review of material, geometry, heat treatment, machining allowance and inspection requirements. The production route is defined before quotation and confirmed against the project specification.
01
Produced to drawings, samples or technical specifications.
02
Forging, heat treatment, machining and inspection.
03
Material, dimensional and test reports supplied.
4340 Steel Forgings We Supply
4340 alloy steel forgings have high strength, high toughness, good machinability, and good corrosion resistance. 4340 alloy steel forgings are ideal blank materials for the manufacturing of large-sized, high-load-bearing components. 4340 forged steel parts have excellent overall performance and are widely used in heavy machinery, aerospace, automotive, energy, shipbuilding, and general machinery industries.
4340 Shaft Forgings
4340 Bar Forgings
4340 Block Forgings
4340 Ring Forgings
4340 Disc Forgings
4340 Gear Blanks
Why 4340 Steel for Heavy-Duty Forgings
4340 forged steel has high strength, high toughness, wear resistance, high temperature stability, good machinability, and corrosion resistance.
High Strength & High Toughness:
4340 steel forgings have high tensile strength and yield strength, while maintaining good plasticityand good impact toughness.
High Hardenability
4340 forged steel has deep hardenability. 4340 steel forgings exhibit uniform hardening in large cross-section parts.
Excellent Fatigue Resistance:
4340 forged steel exhibits excellent fatigue resistance under cyclic loading. Suitable for dynamic loading environments, such as gears and shafts.
Good Wear Resistance:
4340 forged steel parts have good wear and abrasion resistance in their hardened state.
Good Machinability:
4340 steel forgings can be machined using conventional methods, especially in the annealed or pre-hardened condition.
High Corrosion Resistance
4340 steel forgings have good corrosion resistance for harsh environments.
High-Temperature Stability:
4340 steel forgings have high-temperature strength, suitable for harsh environments.
Good Weldability:
We can weld 4340 steel using gas or arc welding.
Heat Treatable:
4340 forged steel is responsive to hardening, tempering, and surface hardening (nitriding, induction hardening).
TYPICAL APPLICATIONS
4340 Steel Forgings Applications:
4340 alloy steel forgings have high strength, high toughness, good machinability, and good corrosion resistance. 4340 alloy steel forgings are ideal blank materials for the manufacturing of large-sized, high-load-bearing components. 4340 forged steel parts have excellent overall performance and are widely used in heavy machinery, aerospace, automotive, energy, shipbuilding, and general machinery industries.
Heavy Machinery
Large gears, driving shafts, hydraulic cylinder parts, tracks, fasteners.
Aerospace Industry
Drive shafts, transmission shafts and load-bearing shafts for industrial machinery.
Automotive Industry
Crankshafts, axle shafts, gears, connecting rods, heavy-duty fasteners.
Oil & Gas Industry
Drilling collars, shafts, valve bodies, wellhead equipment, and fishing tools.
Ship Building Industry
Main shafts, rudder stocks, winch gears, marine propulsion parts.
General Engineering Industry:
Driving gears, heavy-duty shafts, axles, spindles.
MANUFACTURING SCOPE
FORGING AND PROCESSING CAPABILITIES
Actual dimensional and weight limits are confirmed after drawing review.
02
Heat Treatment
Normalizing, annealing, Q&T
03
Machining
Rough & finish machining
04
Testing
UT, MT, mechanical & dimensional
05
Production basis
Customer drawings & specifications
Common 4340 Forged Shapes
4340 Forged Shaft
4340 Forged Ring
4340 Forged Block
4340 Forged Disc
4340 Forged Bar
4340 Forged Gear Blank
4340 Steel Forgings Properties
AISI 4340 alloy steel physical properties information table. AISI 4340 alloy steel mechanical properties information table. AISI 4340 alloy steel thermal properties information table.
| Properties | Metric | Metric Imperial |
|---|---|---|
|
Density |
7.85 g/cm3 |
0.284 lb/in³ |
|
Melting point |
1427°C |
2600°F |
| Properties | Metric | Metric Imperial |
|---|---|---|
|
Tensile strength |
745 MPa |
10800 psi |
|
Yield strength |
470 MPa |
68200 psi |
|
Elongation at break (in 50 mm) |
22% |
22% |
|
Hardness, Brinell |
217 |
217 |
|
Machinability (based on AISI 1212 as 100 machinability) |
50 |
50 |
| Properties | Metric | Metric Imperial |
|---|---|---|
|
Thermal expansion coefficient (@ 0-100°C/32-212°F) |
12.3 µm/m°C |
6.83 µin/in°F |
|
Thermal conductivity (@ 100°C) |
44.5 W/mK |
309 BTU in/hr.ft².°F |
4340 Steel Chemical Composition
4340 steel contains 0.37%-0.43% carbon, 0.70%-0.90% chromium, 1.65%-2.00% nickel, and 0.20%-0.30% molybdenum. AISI 4340 alloy steel chemical composition information for reference.
| Steel Grade | Carbon, C | Silicon, Si | Manganese, Mn | Phosphorous, P | Sulfur, S | Chromium, Cr | Molybdenum, Mo | Nickel, Ni | Iron, Fe |
|---|---|---|---|---|---|---|---|---|---|
|
4340 |
0.370 – 0.430 |
0.150 – 0.300 |
0.600 – 0.800 |
≤ 0.0350 |
≤0.040 |
0.700 – 0.900 |
0.200 – 0.300 |
1.65 – 2.00 |
Balance |
4340 Steel Equivalent
| EU EN | USA |
Germany DIN,WNr |
France AFNOR |
Italy UNI |
Inter ISO |
|---|---|---|---|---|---|
|
34CrNiMo6 (1.6582) |
4340 |
34CrNiMo6 |
35NCD6 |
35CrNiMo6 |
36CrNiMo6 |
4340 Steel Forgings Manufacturer
We are a leading 4340 steel forgings supplier and manufacturer in China.
Our 4340 steel forgings have high strength, high toughness, good machinability, good corrosion resistance, and high temperature stability. Our 4340 steel forgings are widely used in the heavy machinery, aerospace, automotive, energy, shipbuilding, and general machinery industries. Our 4340 forgings are the ideal blank materials for the manufacturing of large, heavy-duty parts, such as gears, shafts, and fasteners.
Feel free to contact us for price information about our 4340 steel forgings.
4140 Steel Shaft Forgings
Have a drawing ready?
Send your drawing, material grade, dimensions, quantity and inspection requirements for manufacturing review.
Custom Forged Parts
Forged Shafts
Custom stepped, flanged, rotor and straight forged shafts supplied forged, heat treated or rough machined.
Forged Tubes
Straight, tapered, stepped and hollow forged tubes supplied with controlled dimensions for finish machining.
Forged Blocks
Square and rectangular forged blocks supplied with custom dimensions, heat treatment and machining.
Forged Rolls
Forged rolls for rolling mills and industrial machinery maufacturing. Heat treated and rough machined.
Forged Discs
Solid, stepped and hubbed forged discs manufactured to custom diameters and thicknesses.
Forged Rings
Seamless steel forged rings produced by ring rolling forging in custom dimensions and material grades.