- What types of Stainless Steel Chain are available, and what are their characteristics?
- What is the difference between NP and NEP Surface Treated Drive Chains?
- What is Lambda Chain?
- How are you handling the production of multi-strand Lambda Chain?
- Is it ok to lubricate Lambda Chains?
- What chain can be used at low temperatures?
- What is the proper direction of installation for spring clips and cotter pins?
- What kind of lubrication is good to use on chains?
- Is grease effective as a lubricant for power transmitting roller chains?
- What is the limit of the chain wear life?
- How much is the initial elongation of Tsubaki chains?
- What kinds of applications require the use of a tensioner?
- What are some counter measures for chain sound?
- Why is the maximum allowable load of Stainless Steel Chain so low?
- What are the causes of and counter measures for rotational deviation of the sprocket?
- How does a Pin Gear drive work?
- What are the values of elastic elongation for RS Roller Chain and Lambda Chain?
- What are the drive formations and characterizations of Roller conveyors?
- What types of certification is there for chains?
- Are there chains that meet the RoHS directive?
1. What types of Stainless Steel Chain are available, and what are their characteristics?
Stainless steel is generally favored for its resistance to corrosion, chemicals and heat. With general focus on machinery for the food production industry, Tsubakimoto Chain offers the various chains listed below that utilize the many beneficial properties of stainless steel, for a wide variety of industries.
| Series | SS Series | AS Series | NS Series |
|---|---|---|---|
| Materials |
|
|
|
| Characteristics |
|
|
|
- Poly Steel Chain, chains with plastic inner plates and stainless steel outer plates which allows for lube-free & low noise use, and lower overall chain weight, are also available.
2. What is the difference between NP and NEP Surface Treated Drive Chains?
Compared to steel chains, stainless steel has superior corrosive resistant capabilities, but its strength (maximum allowable load) is below 1/8 that of steel chains. For applications that require the same strength levels as normal steel chains, as well as superior corrosive resistance abilities, there are the NP and NEP series of Surface Treated Dive Chains. (However these do not provide the same levels of anti-corrosion as stainless steel chain.)
The main characteristics of NP/NEP chain are listed below:
| Steel | NP | NEP | |
|---|---|---|---|
| Color | Dark Blue | Light Silver | Light Grey (Rollers: Dark Grey) |
| Strength Ratio | 100 | 85 | 100 |
| Corrosive Resistance | Poor | <-----------------> | Good |
| Strengths | All Purpose Low Cost |
Superior Appearance Slight Corrosive Resistance |
Superior Corrosive Resistance RoHS Compliant = Environmentally Friendly |
| Weaknesses | Not suitable for applications requiring corrosion resistance | Lower strength than steel | Limited types of chains available |
| Main Applications | General Power Transmission Lowering/Raising Application |
Applications where exterior appearance is highly important: office equipment, specialized machines, etc. | Use in outdoor, marine, etc., environments |
- Strength comparison: based on an approximate value of 100 for steel chain
3. What is Lambda Chain?
To control chain wear elongation and ensure a long running life, lubrication
is critical in any chain application. However, as listed below, there are many instances
where chains are used without lubrication.
- There is the concern of spattering oil contaminating products.
- Wish to maintain a "clean" environment.
- Lubrication is difficult/impossible due to chain location (i.e.: height)
- The cost of lubrication and maintenance.
- Time and labor required to carry out lubrication.
Without requiring additional lubrication yet still providing a comparatively long wear life, Lambda Chain (lube-free chain) can solve all of these problems.
Lambda Chain's construction can be seen in the image here. Note the use of the sintered bush.
By providing lubrication through impregnating the pours of the sintered bush with oil, Lambda Chain is able to provide 7 times the wear life of RS-Roller Chain when used without additional lubrication (14 times for RS40-LMD-1 ~ RS60-LMD-1). However, RS120-LMD-1 and RS140-LMD-1 provide 2.5 times the wear life.
Since its launch in 1988 lambda chain has been adopted for diverse industries and applications, contributing to the reduction of required maintenance, improving working environments, and increasing production.
4. How are you handling the production of multi-strand Lambda Chain?
At the time of its launch Lambda chain was only available in single strands. Following its launch though Tsubaki received may requests for double strand Lambda Chain, and so in 2001 it was made an official product and added to Tsubaki's catalogs.
Please note though that Lambda Chain's measurements, kW ratings, and maximum allowable load differ from that of RS Roller Chain.
<Comparison of Double Strand Chains>
| Multi-strand Coefficient: Multiply the single strand kW rating and maximum allowable load by the following coefficient. | Sprocket | Measurement Comparison | |
|---|---|---|---|
| RS Roller Chain | 1.7 | Sprocket for double strand RS Roller Chain | ---- |
| Lambda Chain (LMD) | 1.4 | Specialty Sprocket (Different transverse pitch for double strand chain) | Thickness of inner plate and dimensions of the chain's outer width differ |
| Heavy Duty Lambda Chain(LMD-H) | 1.7 | Specialty Sprocket (Different transverse pitch for double strand chain) | Thickness of outer and middle plate is one size up compared to LMD double strand chain |
| Lambda Plus a Attachments RS Type Chain (LMC) | Same as LMD single strand Note) (RS Roller Chain (LMC) with Attachments × 1.4) | Sprocket for double strand RS Roller Chain | Same exterior measurements as RS Roller Chain |
Note) Double-strand LMC can be used with RS sprockets, but as the maximum allowable load is lower that of standard drive chains, strength levels are not compatible.
- Please note that due to various performance issues, Lambda Chain is not produced in triple-strand or above configurations.
5. Is it ok to lubricate Lambda Chains?
Lambda Chain is generally well suited for applications where additional lubrication is either undesired, or simply impossible. If it is possible to carry out regular chain lubrication, a longer wear life can be expected from RS Roller Chain, so in this situation we suggest RS Roller Chain. (By carrying out proper lubrication on Lambda Chain, chain life can be extended as shown in the below graph.
<Lubrication Essentials>
- Lube-Cycle
From the start, Lambda Chain bushes are impregnated with lubrication, allowing for a longer period before additional lubrication needs to be applied when compared to standard RS Roller Chain. (However, after the second application, the lubrication cycle becomes the same as standard RS Roller Chain.) The effective period for additional lubrication is the area just before the sudden increase in elongation show in the graph above (Point A). Even if lubrication is added after this point, large increases in wear life cannot be expected. If brown rust dust is discovered in-between the plates of the chain, the lubrication in the bush has already run dry. This changes depending on the conditions of the application, but as a rough standard, please carry out lubrication every 1 - 3 days. - Type of Lubrication
Mechanical Lubrication or synthetic lubrication is ok, but high pressure hydraulic oil or gear oil is recommended. - Viscosity
This changes depending on the conditions of the application, but in general a rough standard would be a viscosity of ISO VG68~220.
<New Products>
Long Life Lambda Chain (X-L® [X-Lambda]), a Lambda Chain with an even longer chain life than standard Lambda Chain, is also available.
6. What chain can be used at low temperatures?
There are several issues to consider when using chain in low temperature environments such as freezers, etc.
- Impact strength drops due to low temperature brittleness
- Solidification of lubrication
- Poor articulation due to frost/ice developing on the chain
Tsubakimoto Chain offers a cold resistant chain that utilizes different materials and a different heat treatment process than RS Roller Chain that can be used at low temperatures. However, issues with lubrication solidification and poor articulation due to frost/ice developing on the chain do not change, so please add cold resistant oil to the chain at initial installation as well as on a regular basis during operation.
Rough standards for using roller chain in cold environments can be seen below.
| RS Roller Chain (for RS80 and above) | Cold Resistant Chain | |
|---|---|---|
| Below -60°C | -- | Unusable |
| -60°C~-50°C | -- | Listed Value × 1/2 |
| -50°C~-40°C | Unusable | Listed Value × 2/3 |
| -40°C~-30°C | Listed Value × 1/4 | Listed Value |
| -30°C~-20°C | Listed Value × 1/3 | " |
| -20°C~-10°C | Listed Value × 1/2 | " |
| -10°C~ 60°C | Listed Value | " |
7. What is the proper direction of installation for spring clips and cotter pins?
The connecting links for small size roller chain (RS60 and below) utilize
a spring clip in their construction. Referring to the graphic on the right,
these spring clips must be installed so that the head of the clip is in the
direction of travel of the chain. Be careful not to open the legs of the clip
too wide when installing. 
RS80~RS200 as well as triple-strand small size roller chain utilize cotter
pins in their construction. Referring to the graphic on the right, insert the
cotter pin from the outer side of the link, and open legs so they are about
60°C. Do not re-use cotter pins or buy cotter pins from third parties. - The method of installing spring clips differs depending on the type of chain. Please see the corresponding Tsubakimoto Chain catalog for details.
8. What kind of lubrication is good to use on chains?
Lubrication is an essential element to power transmission by roller chain. If improper lubrication is carried out, the life of the chain will be reached in an extremely short period of time, and unforeseen accidents may occur. Please take special care when in comes to lubrication and your chains.
Below is a list of conditions/chain sizes and recommended SAE numbers.
SAE Number
| Lubrication System | AI・AII・B | C | ||||||
|---|---|---|---|---|---|---|---|---|
| Area Temp. | -10~0 | 0~40 | 40~50 | 50~60 | -10~0 | 0~40 | 40~50 | 50~60 |
| Chain No. | ||||||||
| RS50 and Below | SAE10W | SAE20 | SAE30 | SAE40 | SAE10W | SAE20 | SAE30 | SAE40 |
| RS60・80 | SAE20 | SAE30 | SAE40 | SAE50 | ||||
| RS100 | SAE20 | SAE30 | SAE40 | SAE50 | ||||
| RS120 and Above | SAE30 | SAE40 | SAE50 | |||||
Note 1) Lube Type: AI… By Oil Can/Brush, AII…Drip Lubrication, B…Oil Bath/Lubrication Using a Slinger Disc, C …Forced Lubrication
9. Is grease effective as a lubricant for power transmitting roller chains?
Chain wear occurs between the pin and bush (creating chain elongation), bush and roller, outer plate and inner plate, and the sprocket and roller.
Other than the gap between the sprocket and roller, the gap between the above mentioned parts is very narrow. Because of this, if high viscosity grease doses not fully and completely penetrate these gaps, the chain will show almost no benefits of the lubrication. Please ensure a lubrication of ISOVG32~220(exact figure will depend on environment of use and chain size) is used on the chain. (For types of lubrication to use, please refer to Q8.)
Furthermore, to ensure that lubrication penetrates the necessary areas, lubricate the area between the bush and roller as well as the area between the outer plate and inner plate on the slack side of the chain.For chain for lifting and lowering applications, in the case of trying to prevent resting on the area that is not bent through contact with the sprocket, etc., grease is acceptable to use.
10. What is the limit of the chain wear life?
(1) For RS Roller Chain
When the chain engages and moves along the sprocket, the pin and bush slide against
each other, causing slight wear on the outside of the pin and inside of the bush.
This is what leads to chain elongation.
As chain elongation develops, the chain creeps up on the sprocket teeth until it starts jumping sprocket teeth and can no longer engage with the sprocket. Engagement
[Maximum Percentage of Elongation Before Chain Jumps Sprocket Teeth]
The maximum percentage of elongation allowed before the chain jumps the sprocket
teeth varies according to the number of sprocket teeth. Theoretically, by reducing
the amount of sprocket teeth, the maximum percentage of elongation increases, however,
in reality this will cause a great increase in vibrations, lower the overall strength,
as well as cause a number of other adverse effects. This is why the maximum percentage
of elongation has been set at 1.5% for all sprockets with 60 teeth or less.
| No. of Teeth on Sprocket | Max Chain Elongation (%) |
|---|---|
| 60 and below | 1.5% |
| 61~80 | 1.2% |
| 81~100 | 1.0% |
| 101~110 | 0.8% |
(2) Lambda Chain
For Lambda and X-Lambda chain, the amount of allowable elongation before the chain life is met is about 0.5%. Unlike RS Roller Chain, Lambda is utilized as a lube-free chain, so when the lubrication that has been impregnated into the sintered bushes runs out, it is time to replace the chain. When the lubrication runs out in the sintered bushes, the chain has experienced elongation of 0.5%. When the impregnated lubrication runs out, red wear dust will appear between the plates, and poor chain articulation will occur. These are clear indicators that the chain needs to be replaced.
[Measuring Chain Elongation]
Chain Elongation (%) = (Measured Length - Standard Length)/Standard Length × 100(%)
Standard Length = Chain Pitch × No. of Links
Also, for quick checking of wear elongation, the Tsubaki Chain Elongation Scale is also available.
11. How much is the initial elongation of Tsubaki chains?
Following the initial instillation and running of a chain, sudden elongation occurs due to the chain settling into the machine and distortions in the initial assembly of the chain. This sudden elongation is only at the start, and after that the chain elongates in a very gradual and predictable manner.
This initial period of elongation is generally 0.1%, but thanks to Tsubaki's high precision components, and pre-stretching that takes place after assembly, almost all Tsubaki Roller Chain's initial elongation is kept below 0.05%.
12. What kinds of applications require the use of a tensioner?
(1) For most cases
Excess chain slack can cause chain vibration and noise, lower the life of both the chain and sprocket, cause the chain to jump sprocket teeth, and in certain situation be the cause of unexpected trouble. To avoid these problems a chain tensioner may be used.
By properly adjusting the chain tension with a tensioner, chains can be continuously run at their kW rating for long periods of time. Please take care in not over tensioning the chain.
| Where to Use | General Purpose of Use | |||
|---|---|---|---|---|
| Adjust Slack | Prevent Vibrations | Adjust Tension | Increase the Rotational Angle | |
| 1. Can't adjust center distance | ○ | |||
| 2. Short center distance, slack on top side | ○ | |||
| 3. Both shafts are vertical or close to | ○ | ○ | ||
| 4. Multi-shaft transmission with long total length | ○ | |||
| 5. Forward and Reverse drive | ○ | |||
| 6. Harsh vibrations | ○ | |||
| 7. Long center distance *1 | ○ | ○ | ||
*1 When the shaft distance is over 50 times the chain pitch. Also, when there is a fluctuating load and the shaft distance is greater than 20 times the chain pitch.
(2) Points of Caution
- In general, tensioners are to be installed on a chain's slack side.
If there is frequent forward/reverse drive, it is necessary to install tensioners on both sides. However, please be cautious as this can overload the tensioner. If you wish to use a Tsubaki tensioner, please consult with your local Tsubaki representatives. - By installing the tensioner off the center of the span and therefore closer to the sprocket, you can make larger adjustments with only small movements of the tensioner. In general tensioners are installed closer to the small sprocket on the outside of the chain. By doing this you can ensure the needed rotational angle with the small sprocket.
- When pushing with the tensioner, ensure that chains do not come in contact with one another. Furthermore, chain fluctuation can occur, so ensure that there is adequate space between chains when adjusting the tensioner.
- Ensure that more than 3 teeth of the tensioner sprocket engage the chain.
- In general, it is recommended that the tensioner sprocket and the small sprocket have the same number of teeth.
13. What are some counter measures for chain sound?
Point of Occurrence
- A crashing sound will occur when the chain's rollers strike the bottom of the sprocket teeth
- There is a gap between the roller and bush. Elastic vibration of the bush will produce noises
- Noise from the inner and outer links impacting one another
- Noises due to sprocket vibration
- The sound of liquid (generally air or lubrication) is discharged from gaps in the chain
Counter Measures
- Reduce the Impact Force
- Decrease the chain speed
- Increase the number of sprocket teeth
- Decrease mass by using a smaller chain
- Create a Buffering Effect in Colliding Areas
- Lubricate the base of the sprocket teeth and various gaps within the chain: between plates, bush ~ pin, bush ~ roller)
- Utilize engineered plastic rollers (kW rating will drop)
- Use a TSUBAKI Low Noise Drive Chain which utilizes a spring roller in its design. Compared with Tsubaki's standard RS Roller Chain (pre-lubricated), noise levels of Low Noise Chain are 6~8 dB lower. (Based on in-house testing results)
14. Why is the maximum allowable load of Stainless Steel Chain so low?
The maximum allowable load of Stainless Steel Chain is approximately 1/8th that of steel chain. This is because of a difference in the selection method for the allowable load, which is explained below.
- RS Roller Chain (Steel)
The maximum allowable load of RS Roller Chain is the value derived from the lowest fatigue limit. When a load lower than this value is repetitively applied to the roller chain, fatigue failure will never occur. As long as the load is within this value, and not in a specialized environment, the chain will reach its life through chain wear.
Parts for RS Roller Chain are heat treated. - Stainless Steel Drive Chain (SS Series)
The maximum allowable load of Stainless Steel Drive Chain (SS Series) is the value determined from the chain's wear performance. (Because parts are not heat treated they have a lower hardness level than RS Roller Chain, causing some problems with wear resistance.) If the chain is subjected to a load greater than this value chain elongation will occur at an accelerated rate, causing adhesion wear between the pin and bush, and poor chain articulation. - Stainless Steel Drive Chain (AS Series)
Precipitation hardened stainless steel is utilized on pins and rollers allowing for a allowable surface pressure that is 1.5 times that of SS Series chain. As a result, the maximum allowable load is also 1.5 times that of Stainless Steel Drive Chain (SS Series).
#60
| Tsubaki Chain Number | Maximum Allowable Load kN {kgf} |
|---|---|
| RS60-1 | 8.83 {900} |
| RS60-SS-1 | 1.03 {105} |
| RS60-AS-1 | 1.57 {160} |
15. What are the causes of and counter measures for rotational deviation of the sprocket?
<Speed Fluctuation of Chain >
First, one of the main causes of rotational deviation derives from fluctuation in chain speed. Chains engage the sprocket in a polygonal fashion. As a result, the height of engagement (radius from the sprocket center) differs, as can be seen in drawings A & B below. Because of this, even if the drive sprocket is to perform uniform rotation, variations in chain speed will develop as much as the radius ratio.
The chain speed fluctuation ratio is calculated as shown below.
Chain Speed Fluctuation Ratio = (V2-V1)/V2=1-cos(180°/Z) (Z = Sprocket Teeth)
It is possible to achieve smoother power transmission by increasing the number of teeth on the sprocket so it is generally recommended to use sprockets with more than 15 teeth.
<Rotational Deviation>
Rotational deviation occurs in the drive sprocket because of chain speed and make up of the sprocket. Furthermore, inexact sprocket manufacturing and poor installation can also have an effect on rotational deviation.
By increasing the number of teeth on the drive sprocket (for items with a large diameter) drive becomes smoother, and rotational deviation is reduced.
Also, other than sprocket teeth, rotational deviation is also reduced by checking and adjusting the span pitch.
16. How does a Pin Gear drive work?
For straight drive and large-radius turning operations, a roller chain is used by the drive source (motor, etc) through a reducer. This can result in cost issues and so on, as the chain requires a great deal of space, and precision processing is required for the gears. Pin Gears are perfect in this situation.
For Pin Gear setups, an Attachment Chain is used around the outside of a drum or table in place of a gear drive wheel, and a specially-processed sprocket is used for the pinion gear (see image 1). For linear operation, an Attachment Chain is installed horizontally in place of the rack (see image 2).
| Pin Gear Drive | Roller Chain Transmission | Gear Transmission | |
|---|---|---|---|
| Restrictions on distance between shafts | YES | NO | YES |
| No. of Engaged Teeth | Low | High | Low |
| Speed Ratio Range | No Limit | Up to 1:7 | No Limit |
| Shape of Teeth | Special Teeth | Sprocket Teeth | Involute |
| Engagement Accuracy | Normal | Normal | Precise |
From the above data it can be seen that Pin Gear drive is optimal
- for comparatively large (1:5 and above) reducers
- where rotational accuracy is not particularly important,
- when used at low speeds (chain speed id less that 50m/min)
17. What are the values of elastic elongation for RS Roller Chain and Lambda Chain?
RS Roller Chain: Single Strand
Please see the below graphs for standard indication values.
Lambda Chain: Single Strand
Double Strand
In the case of double strand chains, compared to the values indicated in the above table, the elongation values for a given load are approximately 1/2, however variations do occur. For safety reasons though please set this value to 1/1.7 when determining appropriate design.
<CAUTION>
In reality slight variations occur. As there are no performance guarantees
please understand this value is for reference purposes only. Furthermore, never
place a load greater than the maximum allowable load on the chain.
18. What are the drive formations and characterizations of Roller conveyors?
For Roller conveyors there are single motor drives, line shaft drives, etc., but here we would like to explain the three general drive patterns when using chain.
Please select the proper layout for your application after you fully realize the characteristics of each pattern.
(1) Parallel Type 
- Method
By attaching chains to adjacent rollers, the drive force is transferred from one axle to the next. This is the most common drive method. - Advantages
- Simple chain replacement
- Wear Elongation: The closer to the driving axle, the greater the amount of wear, however, it is possible to change only the elongated section
- Disadvantages
- Chain sagging due to chain elongation can not be adjusted.
As sagging increases, the chain vibrates, and there is the possibility the chain will ride up on the sprocket. --> Tensioners are required. - Lubrication is necessary on every chain.
- Chain sagging due to chain elongation can not be adjusted.
(2) Rack Type
- Type
One example of a rack type is running the chain in a straight line, and having it engage the teeth of the various sprockets.
This is a very simple method, restricted to conveyance of lighter objects. - Advantages
- Corner sections with curved chain and also be utilized
- Because there are no points for chain articulation, elongation due to chain wear is kept to a minimum
- Disadvantages
- Unsuitable for high speed/high load applications
- Cracking of Rollers frequently occurs
- In general, pin gear sprockets are necessary, which makes this an expensive drive method
(3) Cross Method
- Type
Two sprockets are attached to every roller. One is directly attached to the axle, where the other is idles due to bearings in the sprocket, and chains are installed in a crossing formation (when viewed from the side). This way a single chain will drive every other Roller, and thus two chains are required to drive all the rollers. - Advantages
- Load is dispersed between the two chains, so smaller chains may be used, allowing for a more compact layout
- Chain sagging adjustments and lubrication only needs to be carried out at one location
- Reverse drive also possible
- Disadvantages
- Can not replace only a portion of chain
- Depending on the instillation clearance and number of teeth on the sprocket, there are times when a sufficient angle of engagement can not be achieved.
- Width of equipment increases
19. What types of certification is there for chains?
Chains have a variety of uses making them a highly utilized machine element. In order to maintain the performance and compatibility of chains, various international and country specific standards have been established.
Below is a quick introduction to some of these certifications.
| Type of Chain | International Standards | American Standards | Japanese Standards |
|---|---|---|---|
| Roller Drive Chain Including Attachments | ISO 606 | ASME B 29.100 | JIS B 1801 |
| Bush Drive Chain Including Attachments | ISO 606 | ASME B 29.100 | JIS B 1801 |
| Drive or Conveyor Chain
Double Pitch Roller Chain |
ISO 1275 | ASME B 29.100 | JIS B 1803 |
| Leaf Chain | ISO 4347 | ANSI B 29.8M | JIS B 1804 |
Note: Please understand that the above items are not necessarily the same (dimensions, etc.) for each chain type.
20. Are there chains that meet the RoHS directive?
All of Tsubakimoto Chain Co.'s drive and conveyor chains meet the RoHS directives and regulations.
What are the RoHS Directives?
These are directives aimed to prevent the negative impact of hazardous substances on both people and the environment by restricting the use of those hazardous substances in electrical/battery operated devices, with the EU. RoHS stands for [Restriction of the use of certain Hazardous Substances in electrical and electronic equipment].
Hazardous materials and their content percentages as Outlined in the RoHS directives.
| Lead | Below 1,000ppm (0.1wt%) |
| Mercury | Below 1,000ppm (0.1wt%) |
| Cadmium | Below 100ppm (0.01wt%) |
| Chromium Hexavalent | Below 1,000ppm (0.1wt%) |
| PBB | Below 1,000ppm (0.1wt%) |
| PBDE | Below 1,000ppm (0.1wt%) |
