“Specialists at Criterion Equipment take a look at the importance of taking good care of fork attachments on forklift trucks and provide important advice on how to do so.
“The metal fork attachments used on forklifts may seem indestructible, but eventually they wear out, just like any other machine component. Failure to carry out frequent fork inspections can result in a snapped fork, or a dropped load, which is not only expensive but also dangerous,” explains Heinrich Frederick, Pretoria Branch Manager: Criterion Equipment. “It is also important that operators never carry a load that exceeds the fork’s specific load capacity. The weight capacity of every fork attachment is indicated on the side of the fork shank/face – operators must be made aware of this.
Read more below to learn more about how to inspect forklift forks, which measuring tools you should be using and how to accurately use them.
- Fork Thickness – Forks are constantly subjected to abrasion which can lead to reduced thickness of the fork blades. If the blades are not at the desired thickness, the fork attachment’s lifting capacity can be compromised.
- Check blade and shank/face angle – If the shank/face and blade/heel angle exceed 93 degrees outwards and 87 degrees inwards, the fork must be replaced. Do not bend forks back into place or weld them back in place.
- Inspect forks for surface cracks – Check the entire surface of each fork for cracks. The heel area and hook-on welds are the most likely places for cracks to develop.
- Ensure straightness of blade and shank/face – If the shank/face or the blade is bent, the fork can no longer be used.
- Check fork tip – The fork tip thickness should be inspected. If the fork tip is worn out and too thin, the fork must be replaced or re-machined. To re-machine a fork, the front tip is cut off in order to gain thickness. The tips should also be checked for bends. Should the fork toe have a bend, the fork should be replaced. *To prevent friction on the fork tips, make sure to lift the fork attachment when the forklift is in use / driving around on site.
- Check fork heel – The fork heel is usually one of the first components of the fork that wears out. Make sure that the fork heel is the same thickness as the rest of the fork blade.
- Check weight capacity of fork attachment – This is extremely important as you don’t want to exceed your fork’s load capacity as forks can potentially snap and cause damage to goods. Weight capacity is indicated on the side of the fork shank/face.
- Check latches that attach fork to carriage – Each fork has a fork latch, with a fork pin. The pins ensure that the fork is secured safely on the carriage. This prevents the fork from moving around while driving the machine. The fork latches are the only components that are welded onto the fork.
- Use the correct tools to measure thickness – The metal on a fork can become worn down and reduce in thickness as time goes by. This can lead to forks that are no longer able to handle their original load capacity. Just 10% wear reduces load capacity by 20%, at which point the forks must be replaced. You can measure your fork’s thickness by using a set of tools. Read more below.
In order to measure certain aspects of your fork and ensure that your fork adheres to certain standards, you will be required to use the correct tools in order to do so. There are 3 tools that you can use, namely;
- A measuring card, which can be provided by Criterion Equipment, is used to measure the thickness of the fork’s heel and shank/face.
- Fork Caliper
- Vernier Caliper
Photos (From left to right): Plastic card measurer, Fork calliper, Vernier calliper
- Step 1:
Measure fork shank/face thickness:
Place the card on the side of the fork shank/face. Check the markings indicated on the card. i.e Fork yield thickness = 4
Check fork type:
Whilst keeping your card flat on the side of the fork shank/face, determine the fork type by checking the markings indicated on the card. i.e Fork type = N40
- Step 2:
Measure the thickness of the fork heel:
Move the card from the shank/face to the fork heel. Place the card over the fork heel (as illustrated in the picture to the left).
Fork heel thickness should match fork type (identified in the previous step) i.e. N40.
If the fork heel has a thickness that allows the gap to slide over, the fork is worn out and will have to be replaced. Should the gap on the card fit perfectly on the fork heel without slipping over, the fork attachment adheres to the required measurements/standards.
This instrument is used to measure the fork thickness, the angle of the fork bend and the latch space.
- Step 1:
Measure latch space:
Identify the class of the fork i.e. Class 3. Use fork calliper according to class.
The edge of the calliper is placed below the latch. Don’t place it in the middle where the pin is located, as the calliper will slide in. The calliper should be positioned at the edge of the latch.
If the edge of the calliper slides in between the latch and the fork shank/face, the latch is worn out. The calliper should fit as per the illustrated image to the left.
Photo: Measuring thickness of fork shank/face.
Photo: Measuring the thickness of the fork heel.
- Step 2:
Measure the thickness of fork shank/face and heel:
Fork shank/face and heel measurements should correspond.
Once the calliper is used to measure the fork shank/face thickness, move the calliper over to the fork heel.
Should the calliper slip over the heel, after measuring the fork shank/face, the fork is worn out and will need to be replaced.
- Step 3:
Measure the angle of the fork bend
When using the instrument to inspect the fork angle, the instrument should be flushed to the fork shank/face and the fork heel at the bend of the fork. This is to ensure that no mistakes are made in measurements.
The bend of the fork should not exceed 93 degrees. If it exceeds 93 degrees, the fork is bent and should be replaced.
- Step 1:
Measure the thickness of the fork shank/face:
Place Vernier calliper over fork shank/face to determine thickness.
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- Step 2:
Measure the thickness of the fork heel.
Fork shank/face thickness – 10% = desired heel thickness
Adjust the Vernier calliper to the calculated amount and measure the fork heel to see whether the heel adheres to the calculation. Should the Vernier caliper slip over the heel, the fork is worn-out and should be replaced. Should the calliper fit perfectly, the fork adheres to the required standards.
Calculation Example:
Fork Shank / face measurement = 4.1 > 4.1 – 10% = 3.7 > 3.7 = desired fork heel thickness
Criterion Equipment would like to thank Heinrich Frederick, Branch Manager: Criterion Equipment Pretoria, for sharing these fork safety checks and tips. Heinrich Frederick, Branch Manager: Criterion Equipment Pretoria.012 379 6132
Now that you are aware of all the important checks to do on your fork attachment, make sure that your forks adhere to the required measurements and standards. Should you identify that your fork attachment might not be up to standard and is in need of replacement, don’t hesitate to contact Criterion Equipment.
Have any questions? Give us a call! www.criterion.co.za | 011 966 9700