Because a forklift truck’s chain is classed as a ‘wear’ item, the cost of replacing a worn or damaged one is unlikely to be covered as part of a lift truck contract maintenance package.
However, there are steps that a truck user can take to ensure that the chain – which, of course, controls the critical mast lifting and lowering functions – continues to perform at its peak for the longest possible time.
For example, it is particularly important that chains are lubricated at regular intervals: the life of an adequately lubricated chain is some 60 times greater than that of a dry-running chain and even temporary dry-running will shorten a chain’s working life considerably.
But picking the correct lubricant for leaf chain can make a big difference to a chain’s performance. However, this is not as straightforward as perhaps it should be – largely because most chain lubricants currently used are actually designed for transmission or motorcycle applications!
FB Chain recently undertook a series of tests that graphically illustrate the impact that lubricant has on a forklift truck chain’s lifecycle. Three identical lengths of chain – all manufactured by FB Chain – where coated with three brands of commonly used chain lubricant. The chains were loaded to close to their maximum working load and repeatedly raised and lowered to simulate the action of a forklift truck mast. The first sample seized and would no longer articulate at 40,000 cycles. It was a further 80,000 cycles before the next sample seized and, at the end of the test, the best performing chain oil had outlasted the worst by nearly four times.
Because it’s a fact of life that few forklift operators take the trouble to re-oil the chain regularly enough to achieve the chain’s optimum life, it is important to use a lubricant that is not easily washed off – especially if the forklift is working outside, has to be washed down regularly or operates in and out of a cold store or other environment where condensation build-up can be a problem.
In another test, FB Chain applied the same three lubricants that were used in the wear test to three identical lengths of our own leaf chain, before rinsing the chains with water for one minute then putting them through a salt spray test, where a hot salt water mist was blown over them at regular intervals. The purpose of rinsing the chain with water beforehand was to simulate normal usage when a chain is used in outdoor applications or cold stores. This process allowed us to assess corrosion resistance without having to leave the chain outside for months or even years on end.
Interestingly, the oil that had been the second best performer in the wear test did not come out of the corrosion test at all well. The oil proved to have a low viscosity level, which helps the oil to penetrate between the chain’s pins and plates, but allows it to be easily removed when washed. This resulted in the chain showing drastic signs of corrosion after a mere 15 hours in the salt spray booth. For equipment working outside, this particular brand of oil would not stay in place long enough to perform its main function of lubricating the chain.
I am pleased to say that of the three oils tested, one clearly offered the best performance in both the corrosion and wear tests and this is the brand that is applied to our leaf chain when it leaves our factory.