Forklift forks, also known as tynes or blades, are not one-size-fits-all. They come in a variety of sizes and are classified by the Industrial Truck Association (ITA) to ensure compatibility with your forklift's carriage and load requirements. Choosing the right size is critical for safe and efficient operation.
The Three Key Dimensions
Fork dimensions are typically expressed in the order: Thickness × Width × Length. A standard fork size, for example, is 1 ½″ × 4″ × 42″.
1. Fork Thickness
What it is: Measured along the heel or the vertical part of the fork (the shank).
Why it matters: Thickness directly relates to the forklift's lifting capacity. Heavier loads require thicker forks.
Common sizes: 1 ½″, 1 ¾″, 2″, and 2 ½″.
2. Fork Width
What it is: Measured across the face of the blade or heel.
Why it matters: Width provides stability and support for the load.
Common sizes by class:
Class II: Typically 4 inches wide.
Class III & IV: Typically 5 and 6 inches wide, respectively.
3. Fork Length
What it is: Measured from the tip of the fork to the front face of the heel.
Why it matters: The fork must be long enough to properly support the load. A standard rule is that forks should extend at least two-thirds the length of the load to ensure stability and safety.
Common lengths: Standard in-stock lengths are 42″, 48″, 54″, 60″, 72″, and 96″. For standard pallets, 42-inch forks are common.
ITA Fork Classes
ITA hook-type forks are the industry standard. They are classified based on truck capacity and carriage size. Your forks must match your forklift's carriage class.
The table below outlines the five primary ITA classes:
Class Carriage Height Lifting Capacity Typical Fork Width
Class I 13 inches Less than 2,200 lbs Varies
Class II 16 inches 2,200 – 5,500 lbs 4 inches
Class III 20 inches 5,500 – 10,998 lbs 5 inches
Class IV 25 inches 11,000 – 17,600 lbs 6 inches
Class V 28.66 inches 17,602 – 24,198 lbs Varies
Note: There are also less common classes like Class B (used for piggyback or European narrow aisle forklifts) and some forklifts use pin-type forks, which do not follow standard ITA dimensions.
Example Fork Dimensions by Class
The table below shows example measurements for thickness, width, and length you might find in each class.
Class Thickness Width Length Fork Capacity
II 1.25″ 4″ 30″ 3,700 lb
II 1.5″ 4″ 60″ 5,500 lb
II 1.75″ 4″ 72″ 6,800 lb*
III 1.75″ 5″ 48″ 8,200 lb
III 2″ 6″ 120″ 12,600 lb*
IV 2″ 6″ 42″ 12,600 lb
IV 2.5″ 6″ 96″ 21,400 lb*
*Fork capacity may exceed carriage capacity. Always go by the truck's capacity plate.
How to Determine Your Forklift's Fork Class
Measure the carriage height: Measure the distance between the top and bottom carriage bars.
Compare to the chart: Match your measurement to the class chart above.
Check the data plate: The forklift's data plate provides the most reliable information for exact specifications and limitations.
Summary
Forklift forks are sized by thickness × width × length and classified by ITA class, which corresponds to carriage height and lifting capacity. Always ensure your forks match your forklift's carriage class and load requirements. Standard fork lengths include 42", 48", 54", 60", 72", and 96", with Class II forks typically being 4 inches wide and Class III and IV forks being 5 and 6 inches wide, respectively.