The Complete Guide to Chain

5.2.2 Outboard Roller Chain-Side Roller Type

Free Flow Chain: Electric, electronic and precision machinery conveyance

Application Example

Outboard Roller Chain with Side Rollers (Side Roller Chain) is used for free flow conveyance, like DOUBLE PLUS® Chain, in the electric, electronic equipment, and auto parts industries. Usually two strands are used on the equipment (Figure 5.10). Please refer to DOUBLE PLUS Chain, in Applications Section 5.2.1, for typical pallet size and weight guidelines.

Construction and Features

Side Roller Chain is based on standard roller chain with side rollers installed on extended pins. There are three types of base chain:

  1. RF-type (double pitch roller chain) with S-rollers (straight side plates, small rollers).
  2. RF-type (double pitch roller chain) with R-rollers (straight side plates, oversized rollers).
  3. RS-type (figure-eight side plates, small rollers; oversized rollers are not available).

Figure 5.10 Outboard Roller Chain with Side Rollers
Figure 5.10 Outboard Roller Chain with Side Rollers
Figure 5.10 Outboard Roller Chain with Side Rollers
Figure 5.10 Outboard Roller Chain with Side Rollers

You can select various combinations of chain materials; carbon steel, plated carbon steel, various stainless steel materials, and/or engineered plastic. The relation between roller material availability and applicable chain sizes is shown in Table 5.2.

Table 5.2 Outboard Roller Chain (Side Roller)
RS Attachment Type RF Double Pitch Type
Engineered Plastic Roller RS40~100 RF2040~RF2100
Electroconductive Plastic Roller RS40~60 RF2040~RF2060
Steel Roller RS40~160 RF2040~RF2160

Small sprockets can be used with the RS-type to minimize conveyor height.

Because the side roller diameter is larger than the chain pitch for the RS-type, side rollers cannot be installed on every pitch on the same side of the chain. They can be installed on every pitch in alternating positions (Figure 5.11).

In RF-type, the diameter and width of the side roller are different for S-rollers and R-rollers.

When the stopper in a free flow conveyor is released, pallets accelerate to the chain speed. This acceleration is determined by the coefficient of friction between the side roller and the pin. The smaller the coefficient of friction, the longer it takes for the pallets to reach the speed of the chain. Faster acceleration can be accomplished by installing brake rollers. The construction and coefficient of friction of the brake rollers are different for each chain manufacturer. In engineered plastic side roller products from Tsubaki, the coefficients of friction of chain are: with brake, 0.10; without brake, about 0.06.

Selection and Handling

Outboard Roller Chain has the following characteristics compared to DOUBLE PLUS® Chain:

  1. Greater allowable tension for the carbon steel chain (Table 5.3).
  2. More economical. RF2050 chain costs about half as much, and sprockets cost about two-thirds that of the equivalent size of DOUBLE PLUS® Chain.
  3. More noise. Comparing systems with the same pallet speed and sprockets with the same number of teeth, Side Roller Chain emits about 10 to 15 dB(A) more noise than DOUBLE PLUS® Chain.
  4. Because the body of Side Roller Chain is exposed over the guide rail, this chain does not have the same safety features as DOUBLE PLUS .
  5. Snap covers are not available for Side Roller Chain. It is difficult to prevent small objects from falling in between chain components.
  6. Complete kits for Outboard Roller Chain, including the guide rails and other components, are not available. Therefore, you have to create your own system.
Table 5.3 Allowable Tension of DOUBLE PLUS® and Outboard Roller Chains
Chain Type Roller Type RF2040 RF2050 RF2060 RF2080
DOUBLE PLUS® Chain Regular Series
High Friction Series
Outboard Roller Chain Steel Roller
Plastic Roller

(Allowable load kN)


Standard sprockets may be used. In some cases, side rollers may interfere with the sprocket hub. Additional machining of the hub might be required.

Selection and Handling

  1. Although both R-rollers and S-rollers are commonly used in Side Roller Chains, R-rollers should be considered if either of the following conditions exist:
    • The overall length of the machine is more than 10 m.
    • The chain speed is more than 20 m/min.
  2. R-rollers have lower coefficient of friction (without lubrication, R-roller: 0.12; S-roller: 0.21).
  3. Select Side Roller Chain according to the chain tension and allowable roller load. Make sure to consider the tension due to the accumulating mode when you calculate total chain tension.
  4. Side rollers can be installed in alternating positions, staggered or parallel. Staggered rollers tend to allow pallets to run smoother.
  5. Side Roller Chain requires lubrication to reduce wear elongation and to reduce noise level.

NOTE: Lubrication may affect (delay) acceleration; therefore, please apply carefully.

Chains for Special Applications

Side Roller Chain is available in LAMBDA® construction for lube-free operations.

Technical Trends

Chain manufacturers are working on new chain designs that quiet operation noise.

Chain kits, including chain, guides, sprockets, and other components are a focus of chain manufacturer development plans.

Large pitch side roller conveyor chains are available to handle heavier loads.

Figure 5.11 Installation of Side Rollers
Figure 5.11 Installation of Side Rollers