What Is Chain Manufacturing? From Standard Production to Custom Sizing
Chain manufacturing may look, from the outside, like nothing more than interlocking plates and pins, but it is in fact an engineering process in which every step — from material selection to heat treatment, from assembly to pre-tensioning — depends on measurable tolerances. Whether a chain actually reaches the breaking load stated in the catalogue, and whether it lasts three months or five years in the field, is determined by the weakest link in this production chain.
In this guide, industrial chain manufacturing 's six fundamental stages, which mistakes at each stage lead to which type of failure, and what information you need to request from the manufacturer when placing a custom-size (non-standard) chain order. Manufacturing in Ostim since 1986, Ankara chain company Gurur Makina has prepared this guide by drawing on its field experience.
The 6 Fundamental Stages of Chain Manufacturing
1. Material Selection: This Is Where the Chain's Lifespan Is Determined
A chain is not made from a single material. Since each component is subjected to a different type of stress, each requires a different grade of steel:
- Side plates: These are subjected to tensile stress and fatigue. Quenched-and-tempered steels such as C45 are generally used, with alloy steels employed for high-load classes.
- Pins: These are subjected to shear and bending stress, while simultaneously rotating with friction inside the bushing. Case-hardening steels (such as 20MnCr5) are preferred; the surface must be hard while the core remains tough.
- Bushings and rollers: This is where wear and impact are directly absorbed. Case-hardening steels with high surface hardness and a core tough enough to absorb impact are used.
A common mistake is using the same type of steel for all components. In that case, the chain may reach its catalogue value on the test bench, but fail prematurely in the field due to fatigue cracking. For details on how material selection changes depending on the application, see material selection in industrial chain article.
2. Plate Cutting and Hole Precision
The side plates are manufactured using precision cutting (fine blanking). The critical dimension here is the distance between the centres of two holes on the plate; in other words, the pitch. A deviation of just a few hundredths of a millimetre in the pitch accumulates over a 100-link chain, producing a chain that fails to seat on the sprocket, climbs, and wears down the sprocket teeth.
Cutting burrs and micro-cracks at the hole edge are also the starting point for fatigue fracture. In quality production, the hole surface is smooth and burr-free.
3. Heat Treatment: The Invisible but Decisive Step
The stage that most distinguishes quality in chain manufacturing is heat treatment. Pins and bushes gain carbon at the surface through case hardening (carburising), then are quenched to harden and tempered to remove brittleness. The goal is to achieve a hard, wear-resistant surface layer with a tough core that absorbs impact.
Two typical errors occur at this stage:
- Insufficient case-hardening depth: The hard layer stays thin, the bush wears out quickly, and the chain elongates rapidly.
- Incomplete tempering: The part remains very hard but brittle; under shock loading the pin cracks and the chain fails without warning.
4. Surface Treatment: Protection Matched to the Operating Environment
The environment the chain will operate in determines the surface treatment:
- Phosphate coating: In dry, enclosed environments, its oil-retention property eases the initial running-in period.
- Galvanised coating: Provides protection against corrosion in applications exposed to moisture and outdoor conditions. For more detail, see our corrosion and rust prevention guide .
- Stainless steel production: In applications requiring hygiene or chemical resistance, such as food, chemical, pharmaceutical and washing-line uses, the entire chain is manufactured from stainless steel. In this case, while corrosion resistance is gained, the breaking load is lower than its carbon steel equivalent; this trade-off must be borne in mind when making a selection.
5. Assembly and Riveting
The plates are pressed onto the pins, and the chain is closed by riveting the pin ends. Setting the press force correctly is critical: insufficient tightness causes the pin to rotate and the chain to open up, while excessive tightness leads to stress concentration and cracking in the plate.
6. Pre-stressing: The Step That's Often Skipped
A newly manufactured chain elongates somewhat when first loaded, as the clearances between components settle in. In quality production, this "initial elongation" is taken up at the factory under a controlled pre-stressing load. A chain that hasn't been pre-stressed elongates unexpectedly in its first weeks in the field, tension settings keep going out of adjustment, and the maintenance team ends up looking for the cause in the wrong place.
When evaluating a chain supplier, asking whether pre-tensioning has been applied is one of the fastest ways to gauge quality.
Post-Production Inspection: Which Tests Should Be Carried Out?
The checks expected before delivery are as follows:
| Check | What Is Measured | Why It Matters |
|---|---|---|
| Breaking load test | The actual load at which the chain breaks | Verification of the catalogue value |
| Length / pitch tolerance | Total length over a given number of links | Proper seating on the sprocket, and matched length in dual-strand chain systems |
| Hardness measurement | Surface hardness of pins, bushings and plates | Accuracy of the heat treatment |
| Elongation measurement | Permanent elongation after pre-tensioning | Prevention of early tension loss in the field |
For more on documenting these checks, quality control processes in chain and sprocket supply you can find detailed information in our article.
Custom-Size Chain Manufacturing: When Is It Needed?
Standard catalogue chains cover the vast majority of applications. However, custom manufacturing comes into play in the following cases:
- Older or imported machines requiring a non-standard pitch or plate width
- For conveying, pushing or positioning, attachment (with lugs, extended pins or flights) chains
- Special environmental conditions such as high temperature, chemical exposure or food hygiene requirements
- Reproduction from a sample for machines whose spare parts are no longer manufactured
The most widely used among attachment solutions is lugged chain. Rollerless leaf chains, on the other hand, are preferred for lifting and balancing applications; for details, fleyer chain page.
Information Required for Production from a Sample
If you have the old chain on hand, providing the manufacturer with the following measurements will speed up the process:
- Pitch: The distance between the centres of two consecutive pins. For accuracy, measure the total length of 10 links and divide by 10.
- Roller diameter and width (for roller chains)
- Width between the inner plates
- Plate height and thickness
- Total number of links and the attachment spacing, if any
- Operating conditions: speed, load, temperature, environment (moisture, chemical exposure, food contact)
For the measuring method and comparison with standard tables, chain sprocket dimensions our page will be helpful.
Frequently Asked Questions
How long does custom-size chain manufacturing take?
The lead time varies depending on whether the chain is derived from a standard profile and whether an attachment is required. For attachment chains that can be produced with existing dies, the lead time is short; for fully custom profiles requiring a new die, die preparation time is added. For an exact lead time, it is best to submit a quote request along with your application details.
I don't have a sample, only the machine brand. Can production still be carried out?
The chain type can often be determined from the machine's brand and model. However, since the same model may use different chains in different production years, sending a piece of the old chain or precise measurements, where possible, eliminates the risk of error.
Is Stainless Steel Chain Superior to Carbon Steel in Every Environment?
No. Stainless steel chain offers corrosion resistance, but it has a lower breaking load than a carbon steel chain of the same size. For a high-load application operating in a dry, enclosed environment, carbon steel chain is the more suitable choice.
Conclusion
In chain manufacturing, quality is determined not by a single stage but across all six stages. The right material, correct heat treatment, precise pitch tolerance and pre-tensioning; if even one of these is missing, the chain cannot deliver the performance stated in the catalogue out in the field.
For your custom-size or attachment chain requirements, send us your dimensions and operating conditions, and let's work out the right solution for your application together. Our product ranges can be explored, or you can directly contact us.