Important Factors Which Reduce/Alter Fork Truck Lifting Capacity
November 15, 2021
There are several different factors which will alter or reduce the fork truck lifting capacity, even if no after-market alterations are made to the lift truck. It is important to educate yourself, lift truck operators, and maintenance personnel about how these changes occur and what they need to be checking for to ensure continued safe operations, to help reduce the risks of accidents and potential personal injuries.
When you first received your new Toyota lift truck, it came with a capacity rating and capacity label that is attached to the truck in an area that is easy to see. This information is provided as a guideline to follow but does need to be modified based on the normal usage and wear and tear of the forklift.
You should never cover up or remove the original manufacturer’s capacity label, as it contains other useful information your forklift operators and maintenance personnel need to know. If you accidentally did cover up the original label, contact your forklift distributor immediately and ask for a replacement label.
Aside from properly training your employees on the safe operation, maintenance, and usage of forklifts and lift trucks, you also need to make them aware of the various factors that will reduce and alter lifting capacities.
Factor #1: Fork Wear Reduces Lifting Capacities
The normal “wear and tear” on forks depends on the frequency of use, the weight of items being moved, and what is coming into contact with the forks. For every 1 percent of wear, lifting capacities are reduced by 2 percent.
To illustrate, your capacity label rates the lift truck with a maximum lifting capacity of 5,500 pounds. With 1 percent wear, the maximum lifting weight is reduced by 110 pounds, so the most it can safely lift is 5,390 pounds.
At 10 percent wear, the weight is reduced by 1,100 pounds, so the maximum weight the lift truck can safely handle is 4,400. Ideally, once the forks reach 10 percent wear, it is highly recommended they be replaced with new ones that fit the manufacturer’s specifications for your lift truck.
Factor #2: Chain Wear Reduces Lifting Capacities
Just like the forks, normal “wear and tear” to the chains used with the lifting mechanism will lower safe lifting capacities. A 3 percent reduction in lifting capacity starts to occur with just 1 percent chain wear. Once chains have been worn by 3 percent, they should be replaced with new chains matching the manufacturer’s specifications.
Not accounting for fork wear, going back to our example above using the 5,500 maximum lifting capacity, with 1 percent chain wear, the lifting capacity is reduced by 165 pounds. This wear has to be combined with fork wear to determine the maximum safe lifting capacity.
For instance, if there is 5 percent wear on the forks and 1 percent wear on the chains, the maximum lifting capacity is reduced to 4,785 pounds, calculated as follows:
5 percent fork wear = 10 percent reduction in lifting capacity, which is 550 pounds (5,500 x 10%).
1 percent chain wear = 3 percent reduction in lifting capacity, which is 165 pounds (5,500 x 3%).
550 + 165 = 715 pounds reduction.
5,500 – 715 = 4,785 maximum safe lifting capacity.
Monitoring Forks and Chain “Wear and Tear”
According to the Occupational Safety & Health Administration (OSHA), lift trucks and forklifts need to examined daily prior to being used. In addition, lift trucks used continuously for multiple shifts must be inspected at the beginning of each shift.1
While OSHA does require forks and chains be inspected to look for cracks, breaks, bends, and other such potential damage that could affect the safe operation of the lift truck, they do not require calculating the percentage of wear. However, it is a good idea to get into the habit of calculating the percentage of wear and training your operators how to perform this calculation, too.
The reason we recommend this is because it will allow you to better monitor wear and tear of the forks and chain and know when they are approaching the end of their useful life and will need to be replaced. For assistance in calculating the percentage of wear, feel free to reach out to us, here at Atlas Toyota Material and Handling.
Other Equipment That Alters Lifting Capacity
In addition to normal “wear and tear” of the forks and chains, if you change out forklift attachments or make alterations to extend the length of the forks or alter chains to extend the lifting height, you must recalculate the center of gravity of the lift truck to determine its new lifting capacity.
Factor #3: Fork Extensions and Chain Extensions Lower Lifting Capacities
With fork extensions, for each inch beyond the original length, the center of gravity (i.e., forklift load center) is altered so that it reduces the safe lifting capacity of the truck by 100 pounds. If you were to use a 6-inch extension, the maximum safe lifting weight is reduced 600 pounds, not including any reductions from chain wear and fork wear.
Even the maximum height of the lift is reduced from using fork extensions, and load capacity is diminished at heights ranging between 6 to 8 inches above the ground. Anytime you make “after-market” alterations to your lift truck, you will want to calculate the new center of gravity and new maximum lifting capacity, plus ensure this information is contained on the capacity rating label on the lift truck.
Factor #4: Changing Tires Will Affect Lifting Capacities
Even alterations to the tires will impact maximum safe lifting weights. If you need to replace the tires on your forklift, it is recommended you replace them in sets of four and not one at a time, as this can cause slight alterations to the center of gravity of the lift truck.
Additionally, you need to verify you are replacing the tires with manufacturer recommended tires that are appropriate for your lift. If you are switching from one tire type to another, such as pneumatic to cushion, check with the manufacturer first to see if the new tires are compatible and/or how it will alter lifting capacities.
You also need to make sure you use the same tire size as the original tires. Using a smaller or larger tire size will change the maximum lifting weight of the lift truck. In some cases, it will be necessary to recalculate the center of gravity and maximum lift capacity.
The Toyota Difference
Here at Atlas Toyota Material Handling, we work with our clients to help determine their needs to help them select the most appropriate forklifts. We ensure the capacity rating labels contain precise information and details, such as ratings for different attachments and accessories, when applicable, based on a client’s requirements.
We are more than happy to help our clients and refer them to useful tools and resources they can utilize anytime they change fork attachments or make alterations to their own in-house lift trucks that require recalculating the forklift load center of gravity and maximum safe lifting capacity.
Keep in mind, whenever you make alterations and change attachments, OSHA requires a capacity rating label be secured to the forklift with this new information unless it has been previously calculated and was included on the original label.
In addition to selling and renting new and used forklifts and lift trucks, we offer:
For more information about our forklifts and other equipment, rental programs, parts, maintenance, or training programs, please feel free to contact Atlas Toyota Material Handling at 877-438-2719 today!