4340 Steel Forgings
Custom 4340 steel forgings produced to customer drawings for heavy-duty shafts, forged bars, rings, blocks and high-load industrial components. Available with heat treatment, rough machining, ultrasonic testing and complete inspection documentation.
- Customer drawings
- Heat treatment
- Inspection reports
Built around the
drawing.
Controlled through
delivery.
Every custom forging 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.
PRODUCT FORMS
4340 Steel Forging Forms
Forged Shafts
Heavy-duty, stepped and transmission shafts supplied with machining allowance.
Forged Bars
Round and square forged bars for subsequent machining and component production.
Forged Rings
Ring blanks for gears, bearings, couplings and rotating equipment.
Forged Blocks
Rectangular and custom blocks for dies and high-strength machinery parts.
Need a different forging geometry? Send your drawing and required dimensions for production review.
4340 Steel Forging Overview
AISI 4340 is a nickel-chromium-molybdenum alloy steel used for forged components requiring high strength, toughness and reliable performance under demanding loads.
We supply custom 4340 steel forgings in the form of shafts, bars, rings, blocks and other heavy-duty components according to customer drawings and technical specifications.
Production requirements are reviewed according to the required dimensions, unit weight, machining allowance, mechanical properties, testing scope and documentation requirements.
Additional information
| Material Grade | AISI / SAE 4340 |
|---|---|
| Steel Type | Nickel-Chromium-Molybdenum Alloy Steel |
| Forging Process | Open Die Forging, Ring Rolling |
| Product Forms | Forged Shafts, Forged Bars, Forged Rings, Forged Blocks |
| Supply Condition | As Forged, Annealed, Normalized, Quenched and Tempered |
| Machining Condition | As Forged, Rough Machined, Pre-machined |
| Testing Available | Chemical Analysis, Mechanical Testing, Ultrasonic Testing, Magnetic Particle Testing, Dimensional Inspection |
| Production Basis | Customer Drawing, Custom Specification |
MATERIAL DATA
4340 Steel Forging Technical Data
The following values provide a general reference for AISI/SAE 4340 steel. Final chemical composition and mechanical-property requirements must follow the agreed material standard, heat-treatment condition, section size and customer specification.
Chemical Composition
| Element | Carbon, C | Manganese, Mn | Silicon, Si | Chromium, Cr | Nickel, Ni | Molybdenum, Mo | Phosphorus, P | Sulfur, S |
|---|---|---|---|---|---|---|---|---|
|
AISI 4340 |
0.38–0.43 |
0.60-0.80 |
0.15-0.35 |
0.70-0.90 |
1.65-2.00 |
0.20-0.30 |
0.035 max. |
0.040 max. |
Mechanical Properties
| Property | Tensile Strength | Yield Strength | Elongation | Impact Energy | Brinell Hardness |
|---|---|---|---|---|---|
|
Typical Reference |
850–1,000 MPa |
≥635 MPa |
≥13% |
≥40 J |
248–302 HB |
Applications of 4340 Steel Forgings
4340 steel forgings are commonly selected for components exposed to high mechanical loads, shock, fatigue and repeated service stresses.
Power Transmission
Drive shafts, transmission shafts, pinion shafts, gear shafts and couplings.
Heavy Machinery
Large shafts, forged blocks, spindles, rolls and other load-bearing machinery components.
Oil and Gas Equipment
Forged components for drilling, pressure-control, lifting and power-transmission equipment.
Gears and Rotating Components
Gear blanks, forged rings, hubs and components requiring strength, toughness and fatigue resistance.
MANUFACTURING SCOPE
FORGING AND PROCESSING CAPABILITIES
Actual dimensional and weight limits are confirmed after drawing review.
01
Manufacturing method
Open die forging
02
Materials
Carbon, alloy & stainless steels
03
Heat Treatment
Normalizing, annealing, Q&T
04
Machining
Rough & finish machining
05
Testing
UT, MT, mechanical & dimensional
06
Production basis
Customer drawings & specifications
From drawing review to delivery
01
Drawing, material, quantity, tolerances and standards.
02
Production route, material, machining allowance and lead time.
03
Coordinate manufacturing stages and required quality records.
04
Reports, export packing and shipment support.
Records that travel
with the forging.
Inspection requirements are defined during quotation—not added as an afterthought. Available documentation is confirmed against the project specification before production.
Material certificates & heat traceability
✓
Dimensional inspection report
✓
Ultrasonic / magnetic particle report
✓
Mechanical properties report
✓
Final documentation package
✓
Related Alloy Steel Forgings
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Have a drawing ready?
Send your drawing, material grade, dimensions, quantity and inspection requirements for manufacturing review.
MATERIALS WE FORGE
Carbon Steel Forgings
Custom carbon steel forgings for shafts, rings, discs, blocks and other heavy-duty industrial components.
Alloy Steel Forgings
High-strength alloy steel forgings for machinery, transmission systems and demanding service conditions.
Tool Steel Forgings
Custom tool steel forgings for dies, molds, industrial tooling and other high-load applications.
Stainless Steel Forgings
Corrosion-resistant forged components produced according to customer drawings and specifications.