4340 Shaft Forgings
Custom 4340 shaft forgings manufactured to customer drawings for high-load transmission, energy and heavy-equipment applications. Straight, stepped, flanged and hollow shafts are available with heat treatment, rough machining, ultrasonic testing and inspection documentation.
- Customer drawings
- Heat treatment
- Inspection reports
4340 Forged Shafts for High-Load Applications
AISI 4340 is a nickel-chromium-molybdenum alloy steel commonly selected for forged shafts requiring high strength, toughness, fatigue resistance and through-section hardenability. It is suitable for components operating under combined torsional, bending, impact and cyclic loads.
We manufacture 4340 shaft forgings in straight, stepped, flanged, hollow and drawing-specific configurations. Each project is reviewed according to the finished dimensions, forging allowance, heat-treatment condition, mechanical-property requirements and inspection scope.
The forgings can be supplied in the as-forged, annealed, normalized or quenched-and-tempered condition. Rough turning, machining allowances, ultrasonic testing and inspection reports can be incorporated into the agreed manufacturing route.
Additional information
| Material Grade | AISI 4340 / SAE 4340 / UNS G43400 |
|---|---|
| Steel Type | Nickel-Chromium-Molybdenum Alloy Steel |
| Forging Process | Open-Die Forging |
| Product Forms | Straight Shafts, Stepped Shafts, Flanged Shafts, Hollow Shafts, Custom Shaft Profiles |
| Supply Condition | As Forged, Annealed, Normalized, Quenched and Tempered |
| Machining Condition | Black Forged, Shot Blasted, Rough Turned, Rough Machined |
| Testing Available | Chemical Analysis, Mechanical Testing, Hardness Testing, Ultrasonic Testing, Dimensional Inspection |
| Production Basis | Customer Drawings, Technical Specifications and Approved Inspection Requirements |
PRODUCT RANGE
4340 SHAFT FORGING TYPES
Purpose-shaped components for demanding drive, transmission and rotating equipment.
Hollow Shaft Forgings
Reduced weight and material use without compromising performance.
PRODUCTION RANGE
Drawing-Based 4340 Shaft Production
Every 4340 shaft forging is reviewed as an individual project. Diameter, length, unit weight, section transitions, flange geometry, machining allowance and heat-treatment requirements are confirmed before production.
For an accurate quotation, please provide the finished drawing, required material standard, heat-treatment condition, mechanical properties, inspection requirements, quantity and estimated annual demand.
PRODUCTION RANGE
FOR QUOTATION, PLEASE PROVIDE:
The following information helps us review the forging route, machining allowance and inspection scope.
- Finished drawing
- Material specification
- Heat-treatment condition
- Inspection requirements
- Quantity and annual demand
PRODUCTION PARAMETERS
| Requirement | Available Scope |
|---|---|
|
Diameter |
According to drawing and equipment review |
|
Length |
According to drawing and transport limits |
|
Unit weight |
Up to 20,000 kg, subject to review |
|
Geometry |
Straight, stepped, flanged, hollow or custom |
|
Surface condition |
Black forged, blasted or rough machined |
|
Heat treatment |
Normalizing, annealing, quenching and tempering |
|
Testing |
UT, hardness, mechanical and dimensional testing |
|
Documentation |
MTC and agreed inspection reports |
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
Mechanical properties of 4340 shaft forgings vary significantly with section size, quenching method and tempering temperature. Final tensile strength, yield strength, elongation, impact energy and hardness requirements are therefore confirmed against the customer drawing and agreed material specification.
| Property | Tensile Strength | Yield Strength | Elongation | Impact Energy | Brinell Hardness |
|---|---|---|---|---|---|
|
Typical Reference |
850–1,000 MPa |
≥635 MPa |
≥13% |
≥40 J |
248–302 HB |
MANUFACTURING SCOPE
4340 SHAFT FORGING CAPABILITIES
The production route is developed around the shaft geometry, required forging ratio, heat-treatment condition, machining allowance and inspection specification.
Billets or ingots are forged to improve material consolidation and produce the required shaft profile with controlled machining allowance.
Normalizing, annealing, quenching and tempering can be arranged according to the required material condition and mechanical properties.
Rough turning, boring and machining can remove surface scale, establish reference surfaces and prepare the forging for inspection.
Chemical analysis, mechanical testing, hardness testing, ultrasonic testing and dimensional inspection are available according to the agreed inspection plan.
TYPICAL APPLICATIONS
Applications of 4340 Shaft Forgings
4340 shaft forgings are used where components must withstand high torsional loads, bending stress, impact and repeated operating cycles.
Heavy-Duty Transmission Shafts
Drive and transmission shafts for gearboxes, presses and heavy industrial machinery.
Mining and Energy Equipment
High-load shafts used in crushers, drilling equipment, pumps and energy systems.
Rolls, Mandrels and Arbors
Forged rolls, mandrels and arbors used in metal processing and production equipment.
Gear and Coupling Shafts
Forged shaft blanks for gears, couplings and mechanical power-transmission assemblies.
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
✓
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