With over 30 years of dedicated experience in manufacturing marine stern shafts, our factory has honed its craftsmanship to deliver products that balance durability, precision, and compliance with global marine standards. We’ve served clients across 20+ countries—from shipyards to repair facilities—and our expertise allows us to address even the most specific needs of different vessel types. Below is a detailed breakdown of our stern shafts’ performance, core advantages, and a recent successful transaction with key parameters.

1. Core Performance of Our Marine Stern Shaft

Backed by 30+ years of engineering insights, our stern shafts are designed to withstand harsh marine conditions while ensuring reliable power transmission:

- High Torque & Load-Bearing Capacity**: Forged from premium alloy steel (35CrMo, 40CrNiMoA) and processed with quenching-tempering heat treatment— a technique we’ve optimized over decades. Tensile strength reaches 820-980MPa, yield strength ≥680MPa, and maximum torque capacity up to 55kN·m. This makes them compatible with 600-3200HP marine engines, suitable for bulk carriers, fishing vessels, and small-to-medium cargo ships.

- Exceptional Corrosion Resistance**: We’ve refined our surface treatment process through years of field testing: a two-step process of electroplated chrome (thickness 0.06-0.12mm) followed by passivation. Our stern shafts pass 1200-hour salt spray testing, effectively resisting seawater erosion and marine atmospheric corrosion. Service life is extended to 9-11 years—30% longer than the industry average—reducing clients’ long-term replacement costs.

- Precision & Low-Vibration Operation**: Leveraging 30+ years of machining expertise, we achieve IT5 grade accuracy (radial runout ≤0.02mm, coaxiality error ≤0.04mm/m). Equipped with self-lubricating stern shaft bearings (white metal or rubber options, selected based on vessel usage), operating noise is controlled below 72dB, and vibration acceleration ≤2.2m/s²—ensuring smooth navigation even for long-haul ships.

2. Key Advantages: Built on 30+ Years of Industry Know-How

Our decades of experience translate into tangible advantages for clients:

- Global Certifications & Compliance: Having adapted to evolving international standards over 30 years, all our stern shafts are certified by CCS (China Classification Society), ABS (American Bureau of Shipping), RINA (Registro Italiano Navale), and BV (Bureau Veritas). They fully meet IMO (International Maritime Organization) and IACS (International Association of Classification Societies) requirements, supporting seamless integration into global shipbuilding and repair projects.

- Customization for Diverse Vessels: Over 30 years, we’ve manufactured stern shafts for 500+ vessel models—from small fishing boats to medium cargo ships. We offer tailor-made solutions based on clients’ ship type, engine parameters (HP/RPM), and installation space: customizable length (1.8-8.5m), diameter (90-520mm), and connection type (flange or coupling). For regular orders, lead time is 14-18 days; urgent orders (a common need we’ve addressed for years) can be completed in 8-10 days.

- One-Stop Support & Proven Reliability: We don’t just sell products—we provide end-to-end support, a service refined over decades. This includes supplying complete stern shaft systems (shaft body + bearings + sealing devices) to avoid multi-supplier delays, plus free technical consultation (e.g., calculating optimal shaft diameter based on ship speed/draft) from our team of engineers with 15+ years of average experience.

3. Recent Successful Transaction (October 2025)

Our 30+ years of reputation in the marine industry recently led to a partnership with a Singapore-based ship repair company that services Southeast Asian fishing fleets. They chose us for their 1,500HP fishing vessel upgrade project, citing our track record of reliability.

Transaction Details & Stern Shaft Parameters

| Parameter | Specification |

|--------------------------|----------------------------------------|

| Product Type | Marine stern shaft (for fishing vessel) |

| Quantity | 3 sets |

| Material | 35CrMo alloy steel (our signature material for 20+ years) |

| Length | 4.8m |

| Diameter (Shaft Body) | Φ200mm |

| Diameter (Flange End) | Φ250mm |

| Maximum Torque Capacity | 32kN·m |

| Surface Treatment | Chrome plating (0.09mm) + passivation |

| Certifications | CCS + ABS |

| Matching Engine Power | 1,500HP |

| Matching Propeller | 2.6m diameter, 3-blade |

Cooperation Highlights

The client previously used imported stern shafts, which had high costs and 45+ day lead times. They turned to us after hearing about our 30-year expertise—we delivered a sample in 6 days, and testing showed our stern shaft’s vibration amplitude was 18% lower than imports, with a 22% more competitive quotation. Confident in our quality, they signed a 2-year framework agreement, expecting 12-15 sets annually.

4. Invitation to Our Zhoushan Factory

With 30+ years of manufacturing heritage, our Zhoushan factory is a showcase of refined processes—from raw material forging (using alloy steel sourced from trusted suppliers we’ve partnered with for 15+ years) to precision machining and strict quality testing (torque, corrosion resistance, and dimensional checks). We welcome you to visit, tour our facilities, and discuss your needs with our senior engineers.

For 30 years, we’ve built trust through quality—we look forward to building a long-term partnership with you.