42CrMo4 High-Strength Marine Propeller Shaft Free Forging for Ship Drive Systems. The 42CrMo4 High-Strength Marine Propeller Shaft Free Forging is a large open-die forged shaft designed for marine propulsion systems in commercial vessels and offshore ships. It transmits torque from the engine to the propeller, ensuring reliable performance under continuous torsional load and harsh seawater exposure.
Manufactured from 42CrMo4 alloy steel, this forging offers excellent tensile strength, fatigue resistance, and impact toughness, while maintaining dimensional stability during long-term operation. The forging process ensures directional grain flow along the shaft axis, enhancing mechanical integrity under bending and torque stress.
Key Features
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Forged from premium alloy or stainless steels such as 42CrMo4
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Customizable dimensions, with solid or hollow shafts, keyways, taper ends, or flanges
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Ultrasonic tested, machined, and optionally surface-coated for marine use
Available Types include:
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Solid marine propeller shafts for heavy-duty propulsion systems
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Hollow propeller shafts for optimized weight and dynamic balance
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Stern tube shafts with machined bearing surfaces
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Intermediate drive shafts with customized coupling ends and flanges
| Item |
Details |
| Product Name |
42CrMo4 High-Strength Marine Propeller Shaft Free Forging for Ship Drive Systems |
| Material Grades |
- Marine-grade alloy steels: 42CrMo4 |
| Forging Equipment |
- Hydraulic hammers: 5T / 8T / 12T - 3600T open-die forging press for long-axis and large-diameter shaft forging - Supports integrated forging of stepped and flanged shaft sections |
| Manufacturing Process |
Hot Forging → Normalizing / Quenching + Tempering → Ultrasonic Testing → Rough / Semi-Finish Machining → Dimensional & Surface Inspection |
| Forging Ratio |
≥ 3.0 — Enhances grain orientation along shaft axis, improving fatigue performance and structural integrity under bending and torsional vibration |
| Applications |
- Main propeller shafts for cargo ships, ferries, tugboats, and naval vessels - Intermediate drive shafts for marine transmission systems - Stern shafts operating in seawater or lubricated bearing systems |
| Heat Treatment Options |
- Quenched + Tempered for strength and ductility in 42CrMo4 - Solution annealed + aged for stainless materials |
| Testing & Inspection |
- Chemical: Spectrometer verification of alloy composition - Mechanical: Hardness, tensile, yield, impact testing (transverse & axial) - Ultrasonic (UT): Full-length, multi-angle flaw detection - Dimensional: Journal roundness, straightness, concentricity, length, and runout control |
| Value-Added Services |
- Pre-machining: taper ends, flanges, journals, keyways, sealing interfaces - End protection caps, steel banding, seaworthy packaging - Full material traceability: heat number, forging batch, inspection certificate |
Key Features
-
Forged from premium alloy or stainless steels such as 42CrMo4, 34CrNiMo6, or F51
-
Excellent fatigue strength, torsional rigidity, and corrosion resistance
-
Customizable dimensions, with solid or hollow shafts, keyways, taper ends, or flanges
-
Ultrasonic tested, machined, and optionally surface-coated for marine use
Available Types include:
-
Solid marine propeller shafts for heavy-duty propulsion systems
-
Hollow propeller shafts for optimized weight and dynamic balance
-
Stern tube shafts with machined bearing surfaces
-
Intermediate drive shafts with customized coupling ends and flanges
The steel forgings production flow:
Raw material steel ingot into warehouse(test the chemical composition) → Cutting→ Heating(Furnace temperature test) → Heat treatment after forging(Furnace temperature test) Discharge the furnace(blank inspection)→ Machining→ Inspection(UT,MT,Visal dimension, hardness)→ QT→ Inspection(UT, mechanical properties, hardness, grain size)→ Finish machining→ Inspection (dimension)→ Packing and Marking(steel stamp, mark)→ Storage Shipment.
Packaging & Delivery
Rust-preventive coating
Heavy-duty seaworthy wooden boxes
Custom labeling and barcoding
Global shipping support with flexible delivery terms (FOB, CIF, EXW)
Frequently Asked Questions (FAQs)
1. What is your forging weight range?
We produce forged parts ranging from 100 kg to 7000 kg.
2. Do you provide heat treatment and machining?
Yes, we offer full in-house heat treatment, rough, and finish machining services.
3. Which industries do you supply to?
We serve wind energy, heavy equipment, port machinery, transmission systems, and more.
4. What is your production lead time?
With stock: Around 30 days
Without stock: 40–45 days
5. Where is your factory located?
In Changzhou City, near Shanghai, with shipping via Shanghai Port.
Request a Quote
Please send your technical drawings and requirements to us. Our engineers will review and provide you with a professional quotation and solution shortly.
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