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
Forged from premium alloy or stainless steels such as 42CrMo4
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
| 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.
