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Yancheng Longwan Machinery Co., Ltd. HOME / PRODUCTS & APPLICATION / Ductile Cast Iron

Ductile Cast Iron Manufacturers

Ductile Cast Iron is a high-strength cast iron material with comprehensive properties close to those of steel. Spheroidal graphite is formed through spheroidization and inoculation treatment, which significantly improves the mechanical properties of cast iron, especially its plasticity and toughness, making it have quality strength than carbon steel. This good property makes ductile iron widely used in the manufacture of parts that require high strength, toughness and wear resistance in complex stress environments, such as crankshafts, camshafts of automobiles, tractors and internal combustion engines, and casting of general mechanical components such as medium-pressure valves.

Ductile Cast Iron Automotive Parts
Ductile Cast Iron Agricultural Machinery Parts
Ductile Cast Iron Reducer Accessories
Ductile Cast Iron Valve Accessories
Ductile Cast Iron Water Pump Accessories
Ductile Cast Iron Semiconductor Accessories
Ductile Cast Iron Industrial Robot Accessories
Other Ductile Cast Iron Accessories
ABOUT US
Yancheng Longwan Machinery Co., Ltd.
Yancheng Longwan Machinery Co., Ltd.
Founded in 2006, which located next to National Highway 204 in Yancheng City, Jiangsu Province, 40km from the center of Yancheng City, 5km from the center of Dongtai City, 30km from Dafeng District, and 10km from the exit of Baiju Expressway, with convenient transportation. We mainly produce various types of fire-fighting pipe fittings, reducer parts, auto parts, agricultural machinery, and industrial robot parts. Its main customers include SAIC Group, Deere, Bonfiglioli (China), Shanghai Beixu, Yaskawa Electric, etc. As a famous China Ductile Cast Iron Manufacturers and Ductile Iron Castings Factory, our company has a variety of molding equipment, including one vertical sand-shot horizontal parting boxless shot-press molding line with specifications of 610*510*240, 120 boxes/hour, suitable for mass production of small parts; one upper and lower sand-shot horizontal parting boxless shot-press molding line with specifications of 750*650*250, 100 boxes/hour, suitable for mass production of small and medium-sized parts; 3 sets of 1.25T medium-frequency electric furnaces; 3 cleaning shot blasting machines, and now planning a lost foam production line, suitable for 100Kg~1000Kg casting production, and planning an automatic spray painting line and an electrophoretic coating line at the same time, 3 CNC lathes and 3 lathes.
Yancheng Longwan Machinery Co., Ltd.

ODM Customization Expert

Advanced Production & Processing Equipment

Longwan Machinery has a variety of advanced domestic and foreign molding equipment, including 2 fully automatic production lines for clay sand, 1 semi-automatic production line for clay sand, and 1 coated sand production line, with an annual production capacity of 15,000 tons.

Yancheng Longwan Machinery Co., Ltd.

Complete Inspection Flow

Strict Quality Inspection

We have full-process testing equipment: spectrum analyzer, metallographic microscope, universal tensile testing machine, magnetic particle flaw detector, ultrasonic flaw detector, etc.
The above equipment can fully ensure that we can provide customers with high-precision final castings, and at the same time ensure that we meet customers' comprehensive testing requirements for physical and chemical properties of materials, non-destructive testing, high-precision geometric dimension testing, etc.

Professional Casting Expert

Comprehensive Casting Manufacturer

FAQ
  • Q
    Where are your products mainly exported to?
    A

    Our products are mainly exported to multiple countries such as Germany, Japan, Italy, South Korea, and Australia.
  • Q
    How to deliver the goods to us?
    A

    Usually, we ship by sea, which is very convenient for export.

    Of course, if the customer's goods are urgent, we can also air freight them. Ningbo Airport and Shanghai International Airport are both very close to us.
  • Q
    What's the payment term?
    A

    When quoting, we will confirm the transaction method with you.

    For mass production, we usually make a 50% advance payment in advance and then inspect and confirm the shipment before paying the remaining balance.
  • Q
    How to guarantee the quality of your goods?
    A

    Firstly, there will be corresponding inspections after each process, and for the final completed product, we will conduct a full inspection according to customer requirements and international standards;

    Then, we have advanced and complete top testing equipment in the industry: spectral analyzers, metallographic microscopes, universal tensile testing machines, magnetic particle testing machines, ultrasonic testing machines, etc.

    The above equipment can fully ensure the provision of high-precision final castings to customers, while also meeting the comprehensive testing requirements of customers for material physical and chemical properties, non-destructive testing, high-precision geometric dimension testing, and so on.
  • Q
    How many employees of your company? what about the technicists?
    A

    Our company has more than 120 employees, including 10 professional technicians and 5 engineers.
  • Q
    How about the capacity of your company?
    A

    We have 2 fully automatic clay sand production lines, 1 semi-automatic clay sand production line, and 1 coated sand production line, with an annual production capacity of 15000 tons.
  • Q
    Do you have some standard parts?
    A

    No, currently we produce and customize according to the requirements based on the drawings provided by the customer.
  • Q
    Can you do customized products?
    A

    Yes, we are mainly doing customized products according to the customers’ drawings or samples.
  • Q
    What applications do your products relate to?
    A

    Our products cover almost all the applicable equipment manufacturing and machinery manufacturing and processing fields, mainly including automotive trucks, engineering machinery, agricultural machinery, reducers, water pumps, water treatment systems, and other fields.
  • Q
    what products can you offer?
    A

    We mainly produce cast iron parts made of gray cast iron and ductile iron materials.
  • Q
    Are you a direct manufacturer or trading company?
    A

    We are a foundry and a manufacturer of cast iron parts.
  • Q
    How long can I get the feedbacks after we sent the inquiry?
    A

    We will reply to you within 24 hours of the working day.
NEWS
Ductile Cast Iron Industry knowledge

Ductile Cast Iron Castings Produced to Your Drawings

Yancheng Longwan Machinery Co., Ltd. is a Ductile Cast Iron manufacturer working from a 33,300 m2 foundry in Caoyan Town, Dafeng District, Yancheng City, Jiangsu. Since 2006 we have poured, cleaned, machined and inspected spheroidal graphite iron components to customer drawings and samples, with an installed capacity of 15,000 tons per year.

Our ductile iron range covers automotive and construction machinery parts, agricultural machinery parts, reducer accessories, valve accessories, water pump accessories, semiconductor accessories, industrial robot accessories and other ductile iron accessories, alongside a separate ductile iron pipe fitting range. Customers including SAIC Group, Deere, Bonfiglioli (China), Shanghai Beixu and Yaskawa Electric build these castings into braking, suspension, drivetrain, hydraulic, water handling and automation equipment.

Ductile iron is chosen where a component must carry load, absorb impact and still be produced as a cast shape at economical cost. Nodular graphite gives the material tensile strength and elongation in a range closer to steel, while retaining the casting fluidity, damping and machinability of iron.

Our Ductile Cast Iron Product Range

Each family below is produced with the same route: pattern and process design, melting and spheroidisation control, moulding on automatic or semi-automatic lines, shot blasting, machining where required, and final inspection before packing.

Product family Typical castings Service conditions Specification focus
Ductile Cast Iron Automotive Parts Calipers, brackets, support arms, cylinder blocks Braking, suspension and engine duty with cyclic impact Tensile strength, elongation, pressure tightness, machined datums
Ductile Cast Iron Agricultural Machinery Parts Bridges, brackets and structural castings Field work, shock loading, abrasive soil contact Toughness, wear resistance, weld-free assembly interfaces
Ductile Cast Iron Reducer Accessories Planet carriers and internal transmission accessories High torque, continuous rotation, gear mesh alignment Dimensional consistency, bore position, fatigue strength
Ductile Cast Iron Valve Accessories Pressure-retaining bodies and internal valve components Medium-pressure water and industrial lines Soundness, wall thickness, sealing faces, corrosion performance
Ductile Cast Iron Water Pump Accessories Pump housings, flanges and mounting castings Continuous water contact, water treatment systems Pressure integrity, corrosion resistance, machined flange faces
Ductile Cast Iron Semiconductor Accessories Equipment support and frame castings Vibration-sensitive tooling platforms Mass stability, flatness, machined reference faces
Ductile Cast Iron Industrial Robot Accessories Base, arm and joint-region castings Repeated motion, dynamic loads, positioning accuracy Stiffness, damping, bore concentricity, surface finish
Other Ductile Cast Iron Accessories General mechanical and equipment castings Custom load-bearing or wear-facing duty Grade selection, wall section, machining allowance
Ductile iron Pipe Fittings Fire-fighting pipe fittings and water system fittings Pressure surges, buried and above-ground water service Impact resistance, coating, joint geometry

Where Each Family Fits in Service

Ductile iron is selected part by part, not as a blanket substitute for steel or grey iron. We match the grade and process route to the loading the casting will actually see.

  • Braking and suspension components need nodularity and elongation that resist cracking under repeated stop-and-impact cycles.
  • Transmission and reducer accessories carry torque, so bore position, concentricity and section soundness matter more than raw hardness.
  • Valve and pump castings combine pressure retention with machined sealing faces and corrosion exposure to water and treatment chemicals.
  • Agricultural structural parts survive abrasion and shock, where toughness and consistent wall sections prevent premature failure.
  • Robot and semiconductor castings rely on damping and dimensional stability for positioning accuracy at the machine interface.

Material Grade and Specification Factors We Confirm

Before a pattern is cut, we review the drawing against the melting and moulding process available and agree the measurable characteristics that will be checked at acceptance.

  • Grade and standard — the ductile iron grade is fixed on the quotation, whether it is quoted under a European EN-GJS designation, an ASTM A536 class or a customer material specification.
  • Mechanical properties — tensile strength, yield and elongation are verified from cast test bars; Brinell hardness is measured on a 3T tester.
  • Microstructure — nodularity, nodule count, graphite size and matrix structure are read on a metallographic microscope, with sonic velocity used as a fast consistency check.
  • Chemistry — a German SPECTRO direct-reading spectrometer controls carbon, silicon, manganese, magnesium and trace elements before and during pouring.
  • Soundness and geometry — magnetic particle and ultrasonic flaw detection, wall thickness checks and dimensional inspection are applied according to the drawing's critical features.

Moulding Capacity, Part Size and Production Planning

Moulding line assignment is the first practical question in a ductile iron project, because the flask size and cycle rate determine both tooling design and unit cost. Our vertical sand-shot horizontal parting boxless line runs a 610 x 510 x 240 mm envelope at up to 120 boxes per hour for small parts in series production, and the upper and lower sand-shot horizontal parting line runs 750 x 650 x 250 mm at up to 100 boxes per hour for small and medium-sized parts.

Melting is handled by three 1.25T medium-frequency electric furnaces, and three cleaning shot blasting machines finish the castings before inspection. Our clay sand capacity includes two fully automatic lines and one semi-automatic line, plus a coated sand line; a lost foam line is planned for the 100 kg to 1000 kg casting range. Annual capacity stands at 15,000 tons.

Moulding sand is tested in house with a SAC hammer-type sample making machine, SWY hydraulic strength testing machine, SSZ vibration-type sand screening machine and SGS double-disc infrared dryer, so green sand strength, moisture and compactability stay inside the process window across a production run.

Machining, Surface Treatment and Assembly-Ready Supply

Castings can be supplied as-blasted, as-machined or finish-coated depending on what the assembly station needs. Our machine shop operates three CNC lathes and three lathes for turning, boring and facing operations, and we plan fixture and datum strategy together with the foundry tolerances so that a cast surface is not asked to carry a tolerance only a machined face can hold.

An automatic spray painting line and an electrophoretic coating line are planned, which will extend corrosion protection for water contact, outdoor agricultural and fire-protection applications. Until those lines are in service, coating requirements are agreed case by case during quotation.

Inspection, Acceptance Testing and Quality System

Longwan Machinery operates a complete IATF 16949:2016 system standard, and quality control runs through the whole process rather than only at final dispatch. Raw material is checked at random, in-process checks follow each operation, and finished parts receive full inspection against customer requirements and applicable standards before shipment.

  • Material performance: SPECTRO spectrometer, universal tensile testing machine, 3T Brinell hardness tester, sonic velocity meter, metallographic microscope.
  • Non-destructive testing: magnetic particle flaw detector and ultrasonic flaw detector.
  • Sand and process control: SAC, SWY, SSZ and SGS equipment for moulding sand properties.
  • Dimensional control: high-precision geometric dimension inspection against the drawing's critical characteristics.

Information We Use to Configure Your Solution

Project input How we use it
2D/3D drawings or a physical sample Pattern design, gating and feeding, casting simulation review and quotation
Material grade and standard Charge mix, spheroidisation and inoculation practice, test bar requirements
Casting weight and envelope dimensions Moulding line assignment and pattern layout
Machining scope, datums and tolerances Allowance planning, CNC and lathe programming, fixture and first-article review
Annual volume and batch size Number of patterns, production scheduling and line hour allocation
Inspection and documentation set Test plan, NDT coverage, dimensional report and material certificates
Surface finish and coating Shot blasting specification, primer or paint system, planned spray and e-coat routes
Packing, marking and destination Export packing design, labelling, pallet configuration and shipping method

Tooling, Customisation, Packing and Delivery

We do not hold a catalogue of standard castings; parts are developed to customer drawings or samples under OEM and ODM arrangements. The working sequence is drawings confirmation and quotation, mould and pattern making, sample castings submitted for approval, series production after confirmation, inspection, then shipment.

Packing design, marking and labelling can be adapted to the receiving plant, and finished goods move by sea through the nearby Ningbo and Shanghai ports, with air freight available when a project schedule demands it. Our after-sales team supports installed parts, spare castings and repeat orders so that a qualified component stays repeatable across subsequent production batches.

Frequently Asked Questions

Which ductile iron product families does Longwan Machinery produce?

We cast ductile iron automotive parts, agricultural machinery parts, reducer accessories, valve accessories, water pump accessories, semiconductor accessories, industrial robot accessories and other custom accessories, plus a separate ductile iron pipe fitting range for fire-fighting and water systems.

Can you cast to a specified grade and supply material records?

Yes. The grade and standard are agreed during quotation, and we verify chemistry with a SPECTRO spectrometer and mechanical properties with tensile and Brinell hardness testing. Microstructure is checked by metallographic microscope, and the inspection and documentation scope is confirmed with the order.

What part sizes can your moulding lines handle?

Our boxless shot-press lines cover 610 x 510 x 240 mm and 750 x 650 x 250 mm mould envelopes, which suits small to medium ductile iron parts in series production. A lost foam line planned for the 100 kg to 1000 kg range will extend capacity to heavier castings.

Do you supply machined castings or only raw castings?

Both. Castings can be delivered shot blasted as-cast, or machined on our CNC lathes and lathes to the datums and tolerances on your drawing. Coating requirements are agreed case by case while our automatic spray painting and electrophoretic coating lines are being brought into service.

What do you need from us to prepare a quotation?

A drawing or sample, the material grade and standard, annual volume and batch size, machining scope, coating or finish requirement, and the inspection documentation your quality system needs. With those inputs we confirm the moulding line, pattern approach and acceptance plan and return a quotation accordingly.

How is quality controlled before shipment?

We operate under an IATF 16949:2016 system standard with checks after each process step. Raw material is sampled, in-process controls follow casting, cleaning and machining, and finished castings are fully inspected against customer requirements and applicable standards before packing.