Machine Chain Selection: How to Pull the Right Chain from the Catalogue
Machine chain selection is often made with the phrase “just send the same as before.” Yet if the old chain is being replaced because it already wore out prematurely, fitting an identical one only postpones the problem to the next breakdown. The right selection is made by evaluating pitch, breaking load, service factor and operating speed together.
In this article, when selecting a machine chain from a catalogue, we cover the steps to follow, the standard size tables, and the most common selection mistakes made in the field. For an assessment specific to your application, Ankara chain company you can consult our technical team.
First Determine the Standard: Series B or Series A?
Industrial roller chains fall into two main standard families. Both may share the same pitch, but their roller diameters and inner widths differ, which means they usually cannot be substituted for one another.
- Series B (ISO 606 / DIN 8187): The European standard. Used across most of the machine fleet in Turkey. Referred to by codes such as 08B, 10B, 12B and 16B.
- Series A (ISO 606 / DIN 8188 / ANSI B29.1): The American standard. Also designated by numbers such as ANSI 40, 50, 60 and 80.
The number at the end of the code indicates the strand count: 08B-1 single row, 08B-2 double row, 08B-3 or triple row. If you need to carry a higher load at the same pitch, increasing the number of rows is often a more suitable solution than moving up to a larger pitch; this way, sprocket diameters and mounting dimensions are preserved.
B Series (DIN 8187) Standard Dimension Table
| Chain | Pitch (mm) | Roller Diameter (mm) | Inner Width (mm) | Min. Breaking Load (kN) |
|---|---|---|---|---|
| 06B-1 | 9,525 | 6,35 | 5,72 | 8,9 |
| 08B-1 | 12,70 | 8,51 | 7,75 | 17,8 |
| 10B-1 | 15,875 | 10,16 | 9,65 | 22,2 |
| 12B-1 | 19,05 | 12,07 | 11,68 | 28,9 |
| 16B-1 | 25,40 | 15,88 | 17,02 | 60,0 |
| 20B-1 | 31,75 | 19,05 | 19,56 | 95,0 |
| 24B-1 | 38,10 | 25,40 | 25,40 | 160,0 |
A Series (DIN 8188 / ANSI) Standard Dimension Table
| Chain | ANSI No | Pitch (mm) | Roller Diameter (mm) | Min. Breaking Load (kN) |
|---|---|---|---|---|
| 08A-1 | 40 | 12,70 | 7,92 | 13,8 |
| 10A-1 | 50 | 15,875 | 10,16 | 21,8 |
| 12A-1 | 60 | 19,05 | 11,91 | 31,3 |
| 16A-1 | 80 | 25,40 | 15,88 | 55,6 |
| 20A-1 | 100 | 31,75 | 19,05 | 87,0 |
Note: Breaking loads are the minimum values specified by the standards and may vary by manufacturer. For critical applications, request test values from your supplier. For measurement methods, see chain sprocket dimensions page.
Selection Calculation: Breaking Load Is Not Used Directly
The most common mistake is comparing the tensile force in the application directly with the breaking load listed in the catalogue. Breaking load is the static value at which the chain fails in a single instance; it is not a continuous working load. The correct approach is as follows:
Step 1: Determine the Actual Tensile Force
In drive applications, the force acting on the chain is calculated from the transmitted power and the chain speed:
F (kN) = P (kW) / v (m/s)
Here, P is the transmitted power and v is the linear speed of the chain. Chain speed, in turn, is found from the number of sprocket teeth, the pitch and the rotational speed:
v (m/s) = (z × p × n) / 60,000
z: number of sprocket teeth, p: pitch (mm), n: rotational speed (rpm).
Step 2: Apply the Service Factor
The calculated force is multiplied by a service factor based on the severity of the operating conditions. The values below are generally accepted approximate ranges:
| Operating Condition | Example Application | Service Factor |
|---|---|---|
| Smooth load, no shock | Electric motor + fan, light conveyor | 1,0 |
| Moderate shock | Mixer, filling line, general machine drive | 1,3 – 1,4 |
| Heavy shock | Crusher, press, mill, sudden load changes | 1,5 – 1,8 |
If daily operating time exceeds 8 hours, this factor is increased further. On a line running three shifts continuously, a noticeably higher factor should be used than for a single shift.
Step 3: Determine the Chain Using the Safety Factor
When the force multiplied by the service factor is divided by the minimum breaking load of the chain being selected, the resulting safety factor is expected, in general machine applications, to be between 6 and 10 . In lifting applications, those involving human safety, or those with intense shock, this value is raised higher.
Example: If the force on the chain after applying the service factor is 2.5 kN, and a safety factor of 8 is targeted, a breaking load of at least 20 kN is required. In this case, 10B-1 (22.2 kN) from the table would be a suitable starting selection.
Don't Overlook Operating Speed and Lubrication Type
As chain speed increases, the selection criterion becomes not just load, but heating and lubrication adequacy as well. While periodic manual lubrication is sufficient at low speeds, drip or oil-bath lubrication is required at high speeds. When the lubrication type is incompatible with the application, the chain wears out far sooner than expected, even if it was correctly selected.
For a comparison of lubrication methods, you can check our automatic and manual lubrication systems article.
The 5 Most Common Selection Mistakes Made in the Field
- Choosing the right pitch but the wrong standard. 08B and 08A share the same 12.70 mm pitch, but their roller diameters differ. The wrong series runs incompatibly with the sprocket, wearing out both in a short time.
- Mistaking the breaking load for the working load. Without applying a safety factor, the chain fails from fatigue much earlier than expected.
- Not replacing the sprocket. When a new chain is fitted to a worn sprocket, the new chain deteriorates rapidly. The chain and sprocket must be assessed together; our sprocket range you can review.
- Not monitoring chain elongation. When chain elongation exceeds a certain limit, the chain climbs over the sprocket teeth. For measurement and replacement timing, see wear inspection and replacement timing article.
- Not accounting for environmental conditions. In humid, chemical or food-contact environments, standard carbon steel chain corrodes; a stainless or coated option should be considered.
Chain Type by Application
- Power transmission, motor-to-machine drive:Transmission chains
- Material handling, production line:Conveyor chains
- Product pushing, positioning, conveyor attachment:Lugged chain
- Lifting, balancing, forklift mast:Leaf (fleyer) chains
Frequently Asked Questions
How do I know which standard my chain is?
The most reliable method is to measure the pitch and roller diameter together. Measure the total length of 10 links and divide by 10 to find the pitch, then measure the roller diameter with callipers and compare it with the tables above. If the pitch matches but the roller diameter differs, it is the other series.
Does a duplex chain carry twice the load of a single-strand chain?
Not exactly twice. Since load distribution between the strands isn't ideal, the catalogue value sits slightly below double that of the single-strand chain. When selecting, use the specific duplex chain's own catalogue value rather than estimating.
My chain has stretched — can I shorten it and keep using it?
This is a temporary fix and isn't recommended. Elongation results from wear between the links; removing a link corrects the length but doesn't renew the worn chain. If the elongation limit has been exceeded, the chain must be replaced.
Conclusion
Selecting a machine chain is a calculation that starts with measuring the pitch and is completed with the service factor and safety factor. Using the catalogue breaking load directly is the most common cause of the costliest downtime.
Send us your application's power, speed and environmental details, and we'll determine the right chain type and sprocket match together. You can create a quote request or you can contact us.