Surface treated drive chain

  • NP Series: nickel-plated roller chain providing a certain level of corrosion resistance as well as good appearance.
  • NEP Series: Roller chain will layers of a special coating.
    This highly durable chain offers superior all-round corrosion resistance, such as to saltwater, chemicals and the elements. RoHS compliant.

List of Model Numbers

※ Click the model No. for detailed information.

No. of strands Model No. Roller dia.
(Bush dia.)
Inner width
of inner link
NP Series NEP Series
6.35 1 RS25-NP-1 --- 3.30 3.18
9.525 1 RS35-NP-1 RS35-NEP-1 5.08 4.78
12.70 1 RS40-NP-1 RS40-NEP-1 7.92 7.95
2 --- RS40-NEP-2
15.875 1 RS50-NP-1 RS50-NEP-1 10.16 9.53
2 --- RS50-NEP-2
19.05 1 RS60-NP-1 RS60-NEP-1 11.91 12.70
2 --- RS60-NEP-2
25.40 1 RS80-NP-1 RS80-NEP-1 15.88 15.88
2 --- RS80-NEP-2
31.75 1 RS100-NP-1 RS100-NEP-1 19.05 19.05
2 --- RS100-NEP-2
38.10 1 RS120-NP-1 RS120-NEP-1 22.23 25.40
44.45 1 --- RS140-NEP-1 25.40 25.40
50.80 1 --- RS160-NEP-1 28.58 31.75

Surface treated drive chain APP Series

Tsubaki's pitting corrosion resistant APP Series features a special surface coating on the pins. This coating does not decrease pin strength while protecting the pin from pitting corrosion, which can lead to fatigue fracture. Its outstanding effects are b

*Pitting corrosion is a type of localized corrosion affecting a metallic surface. The corrosion progresses inward as pits.
When pitting corrosion forms on the pin's surface, those pits can lead to premature fatigue breakage and ultimately chain breaka


1. No loss of strength! Has the same strength as standard steel chain.

2. Chromium free, safe for the environment! The special pin coating does not use harmful hexavalent chromium.

Application Example

The perfect chain for corrosive environments

  • Outdoor use
  • Use at seasides and riversides
  • Use when regular lubrication is difficult

Bucket elevator drive

Because it's used outdoors,
rainwater infiltrates gaps in the cover
and promotes pitting corrosion.

Portside transfer crane

Pitting corrosion occurs easily where there is
exposure to salty air and seawater spray.

Example of fatigue fracture caused by pitting corrosion

Insufficient lubrication or use in corrosive (outdoor) environments leads to pitting corrosion and fatigue breakage.

Applicable chain sizes

Single & double strand RS Roller Chain

Single strand Heavy Duty Roller Chain

Model No. examples

RS80 -APP -1B20T
RS80-SUP -APP -1-F(M)
RS80-HT -APP -1