When you are sourcing chain products, it is easy to get confused by different specifications and grades, and as a result, it becomes difficult to select the chain that best fits your application. Therefore, understanding how a chain is made allows you to judge its strength, safety, and suitable applications more quickly and accurately during the purchasing process, helping you avoid selection errors, unnecessary risks, and cost waste.
If you understand chains from a manufacturing perspective, you can more easily identify the fundamental differences between various chain types, and also more easily judge whether a supplier truly has rich production experience, rather than just selling products.
Raw Material Selection – The Starting Point of Chain Manufacturing
Whether it is a welded chain or a weldless chain, the first step in production is always raw material selection.
Common materials used in chain manufacturing include carbon steel, alloy steel, stainless steel, brass, and copper.
When sourcing the chains, the first thing you need to understand is that material selection ultimately affects the following key performance factors:
- Strength limit
- Weldability
- Heat treatment performance
- Fatigue resistance
- Service life
From a manufacturing point of view, chains with different grades and applications usually require different materials. If the material selection is incorrect, even a well-controlled production process cannot achieve the expected performance. This is why professional chain manufacturers clearly separate materials based on chain grade and application, instead of using one single material for all products.
Chain Forming – A Key Step That Determines Shape and Compatibility
After the raw material undergoes wire drawing and straightening, it will enter the chain-link forming process.
In industrial production, professional chain manufacturers typically use automatic forming equipment to ensure consistency in link shape and dimensions. Depending on chain size and material properties, some larger links need to be bent under heating conditions.
At this stage, the key point is not how the link is formed, but whether:
- The links are symmetrical
- The shape is consistent
- The dimensions are accurate
These factors directly affect load distribution, service life, and compatibility with chain wheels, shackles, connecting links, and other fittings. If forming accuracy is insufficient or the links are not symmetrical, localized stress and wear may occur during use.
Welding – The Fundamental Difference Between Welded and Non-Welded Chains
Before this step, the production processes for welded chains and non-welded chains are largely the same, their real difference lies in whether the welding process is required.
For a welded chain, the formed links are welded to close the loop. In actual production, suitable welding methods are selected based on chain size and grade, and welding is carried out together with burr removal to ensure joint integrity, surface smoothness, and overall stability during subsequent calibration, heat treatment, and use.
Welding quality is one of the main factors affecting chain strength and the safety factor. In international standards such as NACM, ASTM, and EN, welding quality is a basic requirement for a chain to meet application standards. In addition, different welded chain grades require different levels of welding quality. For example, G30, G43, G70, G80 welded chains, etc., the quality of the welding directly affects the working load limit (WLL), the safety factor of such chains, and whether they can be used for traction or overhead lifting.
For non-welded chains, the welding process is skipped. After forming, the chains will proceed directly to burr removal and surface treatment.
Common non-welded chains include Double Loop Chain, Jack Chain, Sash Chain, and Lock Link Chain, etc. These chains focus more on flexibility, function, or appearance and are generally used for light-duty, positioning, connecting, or decorative purposes rather than for load-bearing or lifting applications.
Heat Treatment – Determining the Overall Performance of the Chain
Not all chains require heat treatment. Only welded chains designed for heavy loads enter the heat treatment process, while non-welded chains and light-duty chains do not.
Common heat treatment processes include normalizing, quenching, and tempering. By properly controlling temperature and time, chains can maintain high strength while also achieving sufficient ductility and fatigue resistance.
If the heat treatment process is not properly controlled or the temperature settings are incorrect, the chain’s final performance will be affected, resulting in reduced toughness, lower fatigue resistance, and a shorter service life.
Straightening and Calibration
For welded chains, straightening and calibration are essential steps.
In actual production, welded chain manufacturers straighten the chain through controlled stretching, allowing each link’s shape and pitch to reach a uniform and stable condition. This ensures that the load is distributed evenly during use and prevents individual links from carrying abnormal stress.
Straightening and calibration mainly affect the following aspects of the chains:
- Whether the load distribution is uniform during use
- Whether the operation is smooth, and whether breakage or deformation, etc
- Compatibility with chain wheels, shackles, and other fittings
If strict straightening and calibration are not performed during production, link shapes may become inconsistent, and pitch deviation may increase. Over time, this accelerates wear and amplifies potential system risks.
Surface Treatment
After forming, welding, heat treatment, and calibration, chains are surface-treated according to application requirements. Common surface treatments include:
| Surface Treatment Method | Process | Main Benefits |
| Zinc Plating (Electro / Hot-Dip) | A zinc layer is formed on the chain surface by electrochemical or hot-dip processes to prevent air and moisture from contacting the chain | Improves corrosion resistance, suitable for outdoor or humid environments, and cost-effective |
| Copper Plating (Red / Yellow / Antique Bronze) | A layer of copper or copper alloy is deposited on the chain surface | Provides different decorative finishes while offering basic surface protection |
| Black Oxide Treatment (Black Oxide) | A dense oxide film is formed on the steel surface through a chemical reaction | Provides basic protection, reduces reflection, suitable for indoor or dry environments |
| Powder Coating (Powder Coating) | The powder coating is electrostatically applied to the surface of the chain, then heated and cured to form a relatively thick coating. | Enhances protective performance, multiple color options available, suitable for specific environmental requirements |
| E-Coating (E-Coating) | Coating is uniformly deposited on the chain surface using electro-deposition principles | Uniform coating with good corrosion resistance, commonly used for non-welded chains |
| Passivation (Passivation) | A stable oxide film is formed on the stainless steel surface through chemical treatment | Improves corrosion resistance and service life of stainless steel chains |
| Polishing (Polishing) | Reducing surface roughness through mechanical or chemical means | Retain the corrosion resistance of the stainless steel material itself while improving its appearance |
For both welded and non-welded chains, surface treatment is one of the regular processes. Proper surface treatment not only improves appearance but more importantly ensures stable performance under different environmental conditions.
From a manufacturing perspective, surface treatment should be selected based on the application environment, rather than appearance alone.
Testing – Verification of Chain Performance
Testing is the final critical step in the chain’s production process. Professional chain manufacturers carry out various tests to verify key performance characteristics. Common tests include salt spray testing, tensile testing, breaking load testing, and dimensional inspection, ensuring the chain meets design requirements before delivery.
The main purposes of testing are:
- To verify compliance with relevant international standards (such as NACM, ASTM, and EN)
- To ensure consistency in performance and appearance across different production batches
- To identify potential quality issues
Strict testing allows potential problems to be identified before use, significantly reducing operational risks. Therefore, having accurate and stable testing capability is also an important factor when evaluating whether a chain manufacturer can provide a long-term, reliable supply.
Conclusion
Experienced chain manufacturers usually have more mature solutions for material selection, process control, and quality stability. This experience is reflected in product consistency and long-term supply capability, rather than in a single specification or parameter.
Understanding how the chain is made is not for learning manufacturing details, but for making more informed purchasing decisions. By understanding the production process, you can better evaluate differences in strength, safety, and application suitability, and select the chains and suppliers that truly match your needs.
If you are looking for welded chains, non-welded chains, or complete chain solutions, you may contact Tuohai Hardware. Our technical team can recommend suitable chain solutions based on your specific application requirements.
FAQs
Why does the chain manufacturing process directly affect strength and safety?
The strength and safety of a chain are not determined by a single parameter, but are gradually formed throughout the entire manufacturing process.
Even if two chains have the same design specifications, differences in material selection, welding, or heat treatment control during production can lead to completely different actual working loads and operating stability.
What is the most fundamental difference between welded chains and non-welded chains during manufacturing?
The fundamental difference between welded chains and non-welded chains in manufacturing lies in whether a closed link structure is formed through welding.
This difference determines the essential gap between the two types of chains in terms of safety factor and application fields.
How does raw material selection affect chain performance and service life?
Different materials show clear differences in strength, weldability, heat treatment response, and fatigue resistance.
If the selected material does not match the designed working conditions of the chain, the chain is likely to fail prematurely during long-term use.
Therefore, from a purchasing perspective, whether the material matches the application is often more important than a single strength value.
Why is welding quality so important for load-bearing chains?
In international standards such as NACM, ASTM, and EN, welding quality is one of the key prerequisites for welded chains to meet load-bearing requirements.
For load-bearing welded chains, the strength of the welded area directly determines whether the load can be evenly transferred during operation. If welding is insufficient or unstable, long-term use may create safety risks and may even lead to serious accidents.
How does heat treatment improve chain strength and fatigue resistance?
Heat treatment changes the internal structure of the material, allowing a balance between strength, toughness, and fatigue resistance.
This enables the chain to maintain high strength while also having sufficient ductility, so that stable performance can be maintained during long-term use.
Why are straightening and calibration still required after welding and heat treatment?
During welding and heat treatment, high temperatures can cause internal stress and deformation in the chain structure.
If straightening and calibration are not performed, these deviations can cause individual links to carry abnormal loads during use, resulting in reduced service life.
How does surface treatment affect chain durability and application environment?
Proper surface treatment improves the chain’s ability to adapt to environmental conditions.
It effectively slows down corrosion, reduces surface damage, and helps extend the service life of the chain.
Why do chains with similar appearances show very different performance in actual use?
Similar appearance does not mean identical performance.
Differences in material selection, welding quality, heat treatment processes, and calibration accuracy can all lead to significant performance differences during actual use.
What manufacturing capabilities indicate whether a chain manufacturer is reliable?
A reliable chain manufacturer usually has complete and stable production capabilities, including material control, welding processes, heat treatment, calibration, and testing, all built through long-term and systematic manufacturing experience.
Manufacturing maturity is often reflected in product consistency, batch stability, and long-term supply capability, rather than in a single parameter or certification.
Why is testing an essential part of chain manufacturing rather than just a formality?
Testing is a key step used to verify the final results of chain manufacturing.
Through strict testing, potential problems can be identified before shipment, preventing risks from being passed on to the end user.
Therefore, having accurate and stable testing capability is also an important standard for evaluating the professionalism and reliability of a chain manufacturer.
For product specifications related to this topic, see Your Trusted Stainless Steel Chain Supplier and Stainless Steel Jack Chain Manufacturer.
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