Frequently Asked Questions - FAQ

What does "Ultimate tensile strength" mean?

It means the average value of tensile test results over a period sufficient to represent a process.

It means the maximum load when the chain is pulled to the point of breaking.
(It is also called “Breaking strength” and “Breaking load”.)

Test Method of Ultimate Tensile Streng

As shown in the diagram, a chain consisting of at least five links is fastened into a clamping device and arranged so that it is not subject to stresses from torsion, bending etc. It is then subjected to a gradually increasing tensile force until it breaks, at which point the maximum load is measured.

(Note)1.
Values resulting from the failure of the clamping device are not applicable.
(Note)2.
The clamping device is able to move freely.

What does "Average ultimate tensile strength" mean?

It means the average value of tensile test results over a period sufficient to represent a process.

What does "Assured tensile strenght" mean?

It means the tensile strength that the manufacturer guarantees in transactions with the market in general, or with a specific user. It is generally set according to the minimum tensile strength but may be determined in other ways in other circumstances.

What does "Maximum allowable load" mean?

It means the allowable limit of maximum load T acting on the chain. Maximum load T is generally calculated by the formula below.

The Formula for Computation of “Maximum allowable load”: T = Load acting on the chain * Use factor * Speed factor

Does the allowable load change when using offset links on roller chain?

The maximum allowable chain tension when using offset links on roller chain decreases as shown below.

	Rate of maximum allowable tension
When no link used	100%
Standard coupling link	100%
Offset link	65%

Where do you lubricate the chain?

There are two points crucial to the lubrication of roller chain, as indicated by numbers 1 and 2 in the diagram.

(1) Lubrication between pins and bushings
Lubrication at this point prevents friction between pins and bushings, which are the main cause of roller chain wear.

(2) Lubrication at this point prevents friction between bushings and rollers, reduces noise, and absorbs impact load.

What components does chain comprise?

Conveyor chain comprises components such as link plates, pins, bushes, and rollers. The example below is a standard conveyor chain.

Link Plate: A flat, stamped component, with pinholes and bush holes formed by precision pressing.
Roller: May be made of cast iron, structural carbon steel or case-hardened steel, depending on the chain size.
Bush: Requires wear resistance, so bushes are made of case-hardened steel with surface hardening of the inner and outer surfaces.
Pin: Requires wear resistance and toughness, so carefully selected structural carbon steel is used.

The last digit in the chain’s numeric designation will be 0.
This series has the same roller diameter (outer) as a standard roller chain.
Standard sprockets can be used if they have 30 or more teeth.

Large roller series (R-roller type)

The last digit in the chain’s numeric designation will be 2.
This series has the same roller diameter (outer) as a double-pitch roller chain.
Specific sprockets must be used.

Reference: Dimensions of Double-Pitch Roller Chain for Conveyors (PDF format: 8.6MB)