When leaf chain fails, it's usually the result of a gradual process in which the chain elongates with long-term use. And the more that chain wears, the greater the increase in the actual pitch of the chain.
Any sudden failure can have catastrophic consequences. Which means when you're assessing the safety of industrial materials handling equipment such as forklifts, there's no room for error.
Leaf chain measuring tools
When it comes to assessing wear of industrial chain, there are a variety of chain wear measuring tools that technicians can use. The problem though, is that a simple 'worn/not worn' indication is not always the most consistent, accurate or helpful.
Manual measurement methods such as using a measuring tape or a steel rule, for example, can be subject to a high degree of variation or user error. In fact it's commonly said that an engineer needs to be in possession of two sets of eyes and three sets of hands in order to be sure of gaining any kind of meaningful manual reading of measurement!
There is strong evidence that it is extremely difficult for technicians to be able to accurately find the centre line using purely visual methods.
And using a steel tape also relies on the technician's ability to be able to make a precise manual calculation based on some pretty complex arithmetic. With this comes the very real risk that ten people carrying out the same calculation will come up with ten very different results.
There's also the challenge of making sure that you're measuring over the correct length of chain. If a chain is measured over too long a distance for example, then there's a strong chance that you'll be underestimating the true extent of the wear.
And conversely, if the length of chain being measured isn't long enough, then the technician is going to need a high level of precision - something that isn't always that easy when they're conducting a leaf chain inspection out in the field.
A wide array of leaf chain wear measuring tools are provided as free promotional giveaways. But this means they are often flimsy in design and that the consistency of the results can be a significant issue.
What's preferable is to use a robust, professional chain wear gauge that measures the actual length of the chain, that can make a comparison with the chain's nominal pitch length and that can accurately calculate the percentage of chain wear.
Why use a professional chain wear gauge?
So what are the features that a professional leaf chain measuring tool will offer over the traditional measuring tape or steel rule methods?
- A professional chain wear gauge is easy to use, whether it's in the hands of a complete novice or a skilled engineer
- It provides accurate results that can be easily obtained without having to undergo a series of complex calculations
- The percentage elongation is directly shown in a "percentage wear" window to assure complete clarity of the results
- The incorporation of V-jaws ensures technicians achieve accurate pin location without the need to estimate the position of the pin centre line
- The measurement results are consistent and repeatable which means they can be easily demonstrated to customers or end users
- The chain wear gauge is robust, durable and professional in appearance
- The gauge is precision manufactured and accurately toleranced
- The gauge is designed to ensures complete compliance with the GN15 process
All high-quality leaf chain is manufactured to consistently tight tolerances. As the nominal pitch length extends the fatigue life of the chain is reduced and the ultimate breaking strength is considerably lower.
Accurate chain measurement is crucial. A chain that is elongated by 2% is deemed to be dangerous and should be replaced within a pre-determined time-limit - while a chain that has elongated by 3% will need to be replaced immediately.
Ensuring that technicians are able to accurately measure chain wear, and assess the true percentage of elongation, is essential in ensuring the reliability and longevity of any form of safety-critical materials handling application.