Closed Die Forged Steel Flanges OEM Open Forging Process For Gearbox

Forged Steel Flange 42CrNiMo / C45 – Gearbox and Crane Components – OEM Available

Our Large Size Forged Ring Flanges are manufactured from premium-grade alloy steels such as 18CrNiMo7-6 and 42CrMo, ensuring exceptional strength, wear resistance, and durability. Designed for heavy-duty industrial applications, these forged flanges are ideal for wind turbine gearboxes, marine equipment, port machinery, and large-scale transmission systems. With a gross weight capacity of up to 7 tons, each ring flange undergoes open die forging, followed by precise heat treatment and CNC machining to meet tight tolerance requirements.

We support custom dimensions, heat treatment specifications, and machining processes based on customer drawings or technical requirements. With over 25 years of forging expertise, our flanges comply with ISO, GB, and DIN standards, and are ultrasonically tested for internal quality assurance. Trusted by top-tier clients in wind energy and port equipment sectors.

Key Features:

• Material: 42CrMo, 42CrNiMo, 18CrNiMo7-6, 20CrMnMo, C45, C35

• Forging Type: Open die / Closed die

• Weight Range: 100kg – 7000kg

• Heat Treatment: Normalizing, Quenching + Tempering

• Machining: Rough / Semi-finished / Precision CNC

• Standards: Custom / GB / DIN / ANSI

• Applications: Wind turbines, port cranes, gearboxes, engineering machinery

Custom 42CrMo / 42CrNiMo / 18CrNiMo Forged Shafts, drives for Wind Turbine Gearboxes (100–1000KG). We manufacture custom forged shafts and drive components made from premium alloy steels including 42CrMo, 42CrNiMo, and 18CrNiMo, specifically engineered for wind turbine gearbox applications. These forged parts range from 100KG to 1000KG, and can be tailored to meet your exact design and performance requirements.

Material Options:

• 42CrMo – A high-strength alloy steel with excellent toughness and hardenability, widely used for heavy-duty drive shafts.

• 42CrNiMo – A nickel-molybdenum alloy steel offering superior impact resistance and stability in harsh, low-temperature environments.

• 18CrNiMo – A carburizing alloy steel combining high surface wear resistance with strong core toughness, ideal for long-life gear shafts

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Key Features:

• Weight range: 100–1000KG

• Available in various shapes: stepped shafts, spline shafts, solid or hollow structures

• Forged and heat-treated for enhanced mechanical properties

• CNC pre-machining or rough machining available upon request

• 100% Ultrasonic testing and Magnetic Particle Inspection

Applications:

• Main shafts and input/output shafts in wind turbine gearboxes

• High-torque drive components in renewable energy systems

• Custom transmission shafts for planetary and parallel gear reducers

• Offshore and onshore wind power equipment

Manufacturing Process:

The shafts are produced using open die forging or precision closed die forging, followed by appropriate heat treatment such as quenching & tempering or carburizing. Each part is processed to achieve optimized grain flow and superior fatigue resistance. All products are strictly inspected and can be delivered with pre-machined surfaces to facilitate your final assembly or finish machining.

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.

Why Choose Our Forged Steel Shafts?

✅ 25+ Years of Forging Expertise
✅ In-house Quality Control & Testing Lab
✅ ISO9001 / ISO14001 / ISO45001 Certified
✅ Reliable Partner of Top Gearbox Brands (Goldwind, NGC, ZPMC, etc.)
✅ Customized Dimensions & Tolerances Based on Drawings

Typical Features of Our Wind Turbine Shafts

• High torsional strength & fatigue life

• Optimized grain flow via precision forging

• Crack-free forging surfaces

• Enhanced mechanical reliability under extreme loads

• Full traceability and quality documentation (MTC available)

Frequently Asked Questions (FAQs)

1. What is the typical weight spectrum of the forged components you manufacture? Our forging capabilities encompass a range of components weighing from 100 kilograms up to 7 metric tons.

2. Do you handle downstream processing such as thermal treatment and material removal? Indeed, we provide comprehensive in-house services for heat treatment, encompassing both preliminary and final machining operations.

3. Which industrial sectors are the primary beneficiaries of your forged products? We cater to a diverse array of critical industries, including wind power generation, heavy machinery manufacturing, port infrastructure, power transmission systems, and various others.

4. What are the typical timeframes for the completion and dispatch of orders? For items readily available in our inventory, the standard lead time is approximately 30 days. For custom-manufactured orders, the timeframe generally spans 40 to 45 days.

5. Could you provide information on the geographical location of your manufacturing facility and shipping hub? Our production plant is situated in Changzhou City, strategically located near Shanghai, and we utilize the Port of Shanghai for our shipping logistics.

Request a Quotation

To receive a tailored price assessment and a comprehensive engineering solution designed to meet your specific needs, please forward your detailed technical drawings and requirements to our dedicated team. Our experienced engineers will promptly review your submission and provide you with a professional quotation and a suitable solution.

About CHANGZHOU TIANGONG 

We are a Chinese company with over 30 years of forging experience. Our focus lies in the production of machine free forged products. We take pride in our independent quality assurance laboratory, which ensures that all our products meet our customers’ requirements. 

Our customers and partner value our products and services for 2 reasons: excellence and reliability.

Key figures 

A. Over 30 years professional free forging manufacturing experience

B. The company covers an area of 71,000 square meters

C. The construction area of the production workshop is 12,000 square meters

D. Total number of employees of 158

E. 28 engineering and technical personnel 

F. 59 skilled workers 

G. Annual production capacity is 38,000 tons

H. Steel throughput can reach 56,000 tons

Efficient and reliable solutions for customers

Industrial sector application

We design and manufacture forged parts for all industrial areas applying our experience and unique professionalism and taking the specific requirements of the markets into account. This has led us to become a forging industry leader in all industrial segments and collaborating with leading companies.

A. Wind power generation

B. Port Heavy Machinery

C. Mining

D. Ship Building

E. Chemical industrial

F. Oil industrial

G. Metallurgical industry 

H. Hydraulic industry 

I. Other high-end industrial equipment, gearbox body, parts and etc.

Customized solutions 

Modular processes allow us to engineer a solution for almost every industrial application requiring free forged parts. Our modularity means flexibility, a wide range of options, faster delivery, and most important of all, competitiveness.

All our products and production process have been designed to assure excellent, reliable and long lasting unique mechanical performances, resulting in reduced operating costs and long life.

With a wide range of products and a significant experience gained in most industrial applications, we can also provide complete engineering recommendation for customers.