The Importance of Measuring Your Forks and Lift Chains

Updated: Apr 18, 2019

When it comes to forklift operation, forks and lift chains are put under heavy stress for every load. This means that they are prone to wearing down over time. Heavily worn chains or forks can pose a serious safety risk and affect the performance of your machine. That’s why it’s important to inspect them at least once a year and assess their condition. To ensure that your forks and lift chains are in good repair, we’ve prepared a measuring guide that is applicable to all forklift models. This guide is also represented in a video shown below to give you a visual reference for components and measuring techniques.

LIFT CHAINS

To measure your lift chains, you’ll need to raise the forks slightly off the ground. Having a load on the lift chain will straighten it out for accurate measurement. Once set, inspect the chain for any signs of damage including:

  • Broken pins
  • Cracks
  • Stretching

Now that you’re done inspecting the chain, it’s time to move on to measuring. For this guide, we’ve shown you how to utilize both a plastic gauge and a percentage-based gauge. With the plastic gauge, you’ll first need to determine the “pitch” of the chain. This is the distance between the top and bottom centers of each pin on the same link.

Once you’ve determined the pitch, use the indicating arrow on the gauge and line it up with the top pin of a chain link. Using the arrows at the bottom of the plastic gauge, you can measure the pitch and condition of your chain. If the center of the top pin falls below the top arrow, it might be time to replace the lift chain. When measuring the lift chain, it’s important that you place the gauge as close to the roller as possible as this will give you the most accurate reading.

Please Note: Free lift chains tend to wear at a much faster rate than regular lift chains. This means that they should be inspected on a more frequent basis, at least once every 6 months.

In addition to the plastic measuring gauge, you could also use a percentage-based gauge as shown in the video. For this gauge, use the top section to measure the distance between the top and bottom center pin on the same link. This determines the pitch and the number of links that you’ll need to measure to ensure an accurate reading. Extend the gauge so that it covers the recommended number of links, with the bottom section covering the bottom center pin of the last link. See the video at 2:15 for visual reference.

Once this is done, you’ll receive a percentage-based reading that details the amount of wear on the chain. If this percentage is greater than 3%, the chain must be replaced immediately.

FORKS

When measuring forks, it’s important to inspect them for any signs of damage. These can include:

  • Cracks
  • Bends, warps, and twists
  • Straightness
  • Damaged welds
  • Heel wear and tear

Once you’re done inspecting the forks for signs of damage, you can move on to the measuring process. For this purpose, we’ll be utilizing a “Cascade Go-No-Go Gauge” to determine the condition of the forks through a series of measurements. First, you’ll want to measure your forks for bends by opening the gauge to a 90° angle and placing it on top of the forks. If the measure retains this 90° angle, your forks are free from bends. Refer to 2:43 of the video for a visual representation of this process.

Next, you’ll want to check the heel of the forks for wear and tear. This is a common wear point for most forks as operators pleaseoften drag them across the ground during operation. To test the level of wear, clamp each side of the Cascade Go-No-Go Gauge onto the back of the fork as shown in the video. Lock the clamp and then move it to the blade of the fork. If the contact points of the gauge are unable to pass over the heel, then the blade is in good condition. If the points do pass over the blade, then the fork is in bad condition and should be replaced as soon as possible.

The Cascade Gauge can also be used to check the condition of the fork hooks. Using one half of the gauge, insert the contact point into the hook as shown in the video. There should be a gap between the contact point and the top of the hook. If there isn’t a gap, it may be time to replace the forks. While the forks are removed, it’s a good idea to test the hook pins as well. Simply pull on both pins to ensure that they move freely, and the spring mechanism is functioning correctly.

For measuring the heel of lumber forks, you’ll want to make use of calipers. Lumber fork heels range in size from 1 ¼” to 2” thick when brand new, so it’s important to retain this information when installing the forks on your equipment. Use the calipers to measure the heel of the fork as shown in the video. From here, move the calipers to the bottom of the heel and measure the difference. If there is more than a 10% difference between the two readings, it is time to take the forks out of service.

By following this guide, you’re ensuring that your forks and lift chain are in good condition. This reduces the risk of safety incidents while keeping your forklift in working order.