Petol BA118, Operating Manual, Page: 9 / 24

7
Normal Life Expectancy
A leaf chain’s normal life expectancy can be expressed as a maximum percent of elongation.
This is generally between 2% and 3% of pitch. As the chain flexes back and forth, the
bearing joints (pins and inside link plates) gradually wear from articulation. As with all steel
bearing surfaces, the precision hardened steel joints of leaf chain require a constant film of
oil between mating parts to prevent wear and to resist corrosion.
Lubrication
One of the most important but often overlooked factors is adequate lubrication. In addition to
reducing internal friction, maintaining a film of oil on all chain surfaces will inhibit rusting
and corrosion, this is important as corrosion of highly stressed, hardened steel chain
components can cause a major reduction in the load capacity of leaf chain and result in link
plate cracking.
Protection from corrosion is important in storage as well as in service. The factory lubricant
applied to PETOL
TM
Chain is a “Fingerprint Neutralizing Water-Displacing Corrosion
Preventative.” This is an excellent rust and corrosion inhibitor for chains in storage.
Do not attempt to paint chains. Though painting may help inhibit corrosion, it will seal off
critical clearances and restricts oil from reaching the pin surfaces where it is needed for good
joint lubrication. Do not plate chains or chain components. Highly stressed alloy steel
components are subject to hydrogen embrittlement caused by plating. Periodic relubrication
of chains is the most important factor in extending the life of the chains. There is no lubricant
that is ideal for all situations.
A heavy oil lubricant provides excellent protection during prolonged storage, but is messy to
apply, will attract dirt and other contaminants and is messy to use. These contaminants could
lead to premature abrasive wear of the moving components. When operating in dusty
environments, lubricated chains will accumulate a paste like buildup of grime. At periodic
intervals, this buildup should be removed by cleaning and the chain should be immediately
relubricated. Do not use caustic or acid type cleaners; use a stiff brush and a certified safe
petroleum base solvent.
Light oil-based lubricants penetrate into articulated joints easily but can also be washed off or
rubbed off during use. A light oil-based lubricant must have periodic reapplication of the
lubricant to maintain coverage.
Specialty chain lubricants (wax-based) provide excellent lubrication. They have no oily
residue. They are easy to apply. They can be more expensive than other lubricants and are
subject to being washed off or worn off. Wax-based lubricants must have periodic
reapplication of the lubricant to maintain coverage.
The frequency of relubrication is the most important factor. It will depend on frequency of
use, length of storage between uses, exposure to dust and other contaminants, and exposure to
salt water or other corrosion accelerants. The end user should establish a good preventative
maintenance program for relubrication of all chains and articulated components.