In our purchasing and daily use, many people face the question of how to choose between the G4 chain and the G43 chain. These two chains are both medium to high-strength welded chains. When you choose, it is easy to get confused. If the wrong choice is made, it may not only cause cost waste, but also bring certain risks in use. In this article, we will combine real applications in different industries to help you understand the differences and the typical use range of the G4 chain and the G43 chain more clearly.
Why do we confuse the G4 chain and the G43 chain?
The G4 chain and the G43 chain(also known as “Grade43 chain”) are often confused in use, mainly for the following three reasons:
- First, the G4 chain (also known as “G40 chain” or “Grade 40 chain”) was often used in the early North American marine, industrial, and related markets to describe medium-to-high strength welded chain. With the development of the NACM grade system, grades such as G43 appeared. The name and the use scenarios of G43 are very close to the G4 chain.
- Second, welded chain suppliers do not have a unified way of explaining grades. Some suppliers focus on the grade number, while others focus on the industry name “High Test”. And High Test Chain is a general name for medium-to-high strength welded chain. This further caused confusion during our communication.
- Last, in many applications, the chain grade is not strictly required. As long as the load requirement is met and there are no regulatory restrictions, the G40 chain and the G43 chain can both be used. This also causes these two grades to be mixed and used together in daily work.
What are the differences between the G4 chain and the G43 chain?
In the common grade system of welded chain on the market, G4 and G43 are often classified as High Test chain; however, these two grades are not the same. They have clear differences in grade, working load limit (WLL), and application scenarios. When you choose, you should pay close attention to these differences.
Differences in Standard and Grade
G4 is a high-test chain grade name that emerged in the earlier welded chain market, and it was widely used in early North American industry and marine-related industries.
G43 is a more clear and common grade marking in the NACM system.
In current market, G43 is usually used in industrial chain specifications and sales settings, while G4 is more often kept as a historical name in marine-related fields.
Differences in strength and WLL
For specific mechanical performance, the difference between the G4 chain and the G43 chain mainly shows in WLL (maximum working load) and MBS (minimum breaking strength).
Using common sizes under the NACM system as an example, under the same wire diameter and size:
- G4 is the basic grade of the High Test chain. Its load capacity is higher than G30 proof coil chain, such as the BBB chain, and it can meet many common towing, tie-down, and securing jobs.
- G43 has higher WLL and MBS than the G4 chain, so it can handle higher loads and provides more safety margin.
So, G43 chain usually means higher working load and higher breaking load than G4 chain. It is often used in jobs with higher safety requirements, while G4 chain can meet common medium-to-high strength applications.
Differences in material and production process
- From the material term, both the G4 chain and the G43 chain are made from medium-high strength carbon steel through welding. You cannot separate these grades only by steel type. The real difference is the control requirements for stable material performance and batch-to-batch consistency.
- In welding and forming, the G4 chain mainly meets the basic welding strength and tolerance requirements. G43 chain has stricter requirements for weld quality, size tolerance, and link consistency, to make sure it can still perform reliably under high load.
- In heat treatment, there is also a clear difference between these two types of chains. The main goal of heat treatment for the G4 chain is to meet the rated strength requirement. For the G43 chain, a more accurate heat treatment process is needed to get higher strength and toughness. This helps it handle higher loads and impact conditions, and helps prevent damage and deformation in long-term use due to metal fatigue and local stress concentration.
In the final testing requirements, the difference between the G4 chain and the G43 chain is the most direct. Under the NACM grade system, the required Minimum Breaking Strength(MBS) and Working Load Limit (WLL) for G43 chain are higher than for G4 chain. This can be directly reflected in the WLL data in the specification sheet.
G4 vs G43: Differences in Typical Applications
When you purchase or use the welded chain, what you should focus on is not which grade is higher, but your application requirements for load, safety, and whether the load is long-term. In different scenarios and working conditions, the differences between the G4 chain and the G43 chain become very clear.
Industrial Tie-Down and Load Securing (Non-DOT / Non-highway environments)
In truck moving, equipment securing, and material tie-down (inside factories, job sites, or other non-highway environments), the chain takes steady tension and repeated tightening and releasing. The load is usually predictable, in this case, you only need to select a welded chain whose WLL specification meets the actual load requirements.
If your load value is clear and the working condition is stable, a G4 chain that meets the WLL can cover most common industrial tie-down needs.
If your application needs a higher load margin and safety margin, you can choose the G43 chain with a higher WLL.
It should be clearly stated that, under North American transport rules (FMCSA/DOT 49 CFR §393), G70 Transport Chain or a higher grade must be used for cargo lashing or trailer transportation in road truck transportation; otherwise, it may create enforcement and insurance risks.
Towing, Recovery, and Trailer
In non-highway towing or vehicle recovery applications, the chain usually faces non-steady loads and impact loads. The risk is higher than the common securing and tie-down.
So, in towing and recovery, you should choose the G43 chain with a higher WLL and MBS. It is better for sudden high loads during impact and other uncertain working conditions. In some towing situations with lower force and smoother pulling, you can use the G4 chain.
Compliance note (North American highway transport):
If you do towing or recovery work on North American public highways, you should use the G70 Transport Chain that meets transport rules. Even though the G4 chain and G43 chain are medium-to-high strength welded chains, they are not grades recognized as transport chains in the North American highway transport system.
Agriculture and Farm Equipment
If you use welded chain in agriculture or farm equipment, you need to consider the outdoor use, complex environments, and uncertain maintenance cycles. At the same time, you may care more about cost.
In common agricultural applications, hot-dip galvanized G4 chain is widely used because the production process is mature and the cost is lower, and it can meet most farm working conditions.
If you need to tow large farm equipment and the pulling force requirement is higher, you can choose the G43 chain to get a higher load capacity and safety margin.
Please note that in agricultural environments, besides grade and load, the surface finish of the chain is also very important, because it directly affects the chain’s service life.
Small Vessels and Non-class Anchoring
In small vessel anchoring or non-class anchoring systems, you can choose either G4 chain or G43 chain. In these non-class applications, matching with the windlass and chain wheel, and the surface finish (such as hot-dip galvanized) are more important than whether the chain is G4 or G43 grade.
In addition, if your anchoring load requirement is higher, you can choose G43. If it is a common small vessel, the G4 chain is usually more suitable.
Common Mistakes When Choosing Between G4 and G43 Chains
The grades of G4 chain and G43 chain are not complex. But in real purchasing and use, they are often confused because people have some common misunderstandings in how they think and judge. The following situations are very common in most industries.
Higher Grade is Better
A common mistake is judging only by grade and thinking the G43 chain must be better than the G4 chain. In fact, if your required load is very clear and stable, using a higher-grade welded chain does not bring any safety improvement; it may only increase the cost.
So in the G4 vs G43 chain comparison, the key is not which grade is higher, but whether it matches your need.
Only Looking at Price and Ignoring Load Needs
Another common mistake is using price as the only standard. When the G4 chain and the G43 chain look similar in size and shape, it is easy to pick the cheaper one and ignore the needed WLL. In use, the chain may stay close to the limit load for a long time, which creates a safety risk.
Ignoring the Matching of Fittings
When purchasing or choosing a chain, people may sometimes ignore fittings such as hooks, shackles, and connectors. If the WLL of these fittings does not match the chosen chain, the overall load capacity will be limited by the weakest part. This can create danger, such as breakage during use.
Using a G4 or G43 Chain as a Lifting Chain
This is one of the easiest mistakes to miss, and it is the most risky misunderstandings.
The G4 chain and the G43 chain are medium-to-high strength welded chains. But in heavy overhead lifting, these chains cannot replace a lifting chain. You should use G80 lifting chain or higher grade chain that meets the industry rules. Otherwise, it may bring serious safety risks.
Summary
Overall, the G4 chain and the G43 chain both belong to the High Test Chain series, but in the NACM grade system, they are different grades, with different WLL and testing requirements. In real use, the key is your working condition and load needs, not which grade is “higher”. Only when you understand this difference can you avoid confusion and then choose the most suitable welded chain between the G4 chain and the G43 chain.
If you have more questions about the G4 chain vs the G43 chain, please don’t hesitate to Contact Tuohai. Our technical engineers can provide a comprehensive high-test chain solution and help you make the best choice.
FAQs
Are G4, G40, High Test, and HT chain the same welded chain?
They are not exactly the same. The differences are:
- G4 chain is the common name for High Test chain in the early North American market.
- G43 is a more clear and widely used grade marking in the NACM system.
- High Test or HT chain is an industry general name, usually meaning this type of medium-to-high strength welded chain.
Do G4 / G43 follow ISO standards?
G4 and G43 themselves are not ISO-defined grades.
G4 and G43 are grade classifications in the NACM system, and they belong to the welded chain grade system commonly used in North America.
In real production and testing, the material, size, and test methods can refer to ISO or ASTM standards, but the grade names themselves are not ISO.
Are the dimensions of G4 and G43 the same? Can they be used as replacements?
Under the same gague and wire diameter, the dimensions of G4 and G43 are usually the same. But size is not the only factor for replacement. The more important factor is WLL.
If the required WLL of your work is far below G4, then you can use the G4 chain of the same size instead of G43. Otherwise, it will create a safety risk.
Is there a big WLL difference between the G4 chain and the G43 chain?
In the NACM system, if the wire diameter is the same, the G43 chain has a higher WLL and MBS than the G4 chain, and the exact difference changes with size. This is one of the main differences between the G4 chain and the G43 chain.
Do G4 and G43 have a fixed safety factor?
G4 and G43 do not have a fixed safety factor.
In the NACM system, the safety factor depends on the relationship between WLL and MBS. The value should be based on the specification table and real test data provided by the welded chain manufacturers. It should not be judged only by one fixed multiplier.
Why do G4 / G43 parameters look different from different suppliers?
The main reasons are:
- There are differences in manufacturing processes and testing methods among different manufacturers.
- Different manufacturers use different tolerance standards during production. For example, some only follow the minimum requirements, while others strictly follow the standards.
As long as the chain grade is clearly marked and key parameters (such as WLL and MBS) meet the requirements of its grade, you can buy with confidence. Small differences in parameters between manufacturers are normal.
Can the G4 chain and the G43 chain be used mixed?
It is not recommended to mix them when using.
The load capacity of the whole system is always decided by the part with the lowest WLL. When you mix them, it is easy to make a wrong judgment and create risk.
Can I use a thicker chain size to replace a higher grade?
A thicker wire diameter does not mean a higher grade. Chain grade depends not only on size, but also on material performance and the production process, among other factors. You cannot decide only by a thicker diameter. You need to decide based on WLL and the real working conditions.
Is G43 always better than G4 in towing or recovery?
Not always.
G43 is suitable for towing or recovery with impact loads and uncertain forces.
In stable pulling with clear loads, if the WLL of G4 chain meets the requirement, you can also use G4 chain.
Why can’t G4 / G43 replace G70 for highway transport, even though they are strong?
This is not about strength. It is about regulations.
In the North American highway transport system (FMCSA / DOT 49 CFR §393), cargo securement on public roads must use a G70 transport chain or a higher grade that the rule recognizes. So even if G4 and G43 are strong enough, they are still not considered compliant options.
Can G4/G43 chains be used for overhead lifting?
No.
The G4 chain and the G43 chain are not allowed for any overhead lifting. You should use a G80 lifting chain or a higher-grade lifting chain that meets the rules; otherwise, it will create a serious safety risk.
Which is more durable, G4 or G43? Is there a big service life difference?
The durability of welded chains is not decided only by grade. Service life and durability mainly depend on:
- Surface finish, such as hot-dip galvanized, electro-galvanized, powder coating, etc.
- Use environment, such as moisture and corrosion
- Use conditions, such as wear, long-term load close to WLL, and frequent impact loads
Is G4 or G43 more common in agriculture or small vessel anchoring?
Both are common.
G4 chain is used more widely because the process is more mature and the cost is lower.
If the load is higher and requires a greater safety margin, you can choose the G43 chain.
In these applications, because the environment is more complex and the chain corrodes easily, the choice of surface finish is more important.
For product specifications related to this topic, see Tie Down Chain and Tow Chain.
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