Forklift pallet forks (also called fork tines or blades) are the horizontal steel arms that slide under pallets and loads to lift, transport, and stack materials. They are the most fundamental attachment on any forklift, yet their selection and maintenance are often overlooked until a failure occurs.
Fork Dimensions: Length, Width, and Thickness
Pallet forks are defined by three primary dimensions that determine what loads they can handle and how they fit your carriage.
Length: The most critical dimension for pallet handling. The fork should extend at least two-thirds of the load's depth. Standard lengths include 42 inches (1067 mm) and 48 inches (1219 mm) . Longer forks (54-72 inches) are used for lumber, pipes, and other oversized loads.
Cross-Section: Expressed as Width × Height in millimeters. Common cross-sections include:
Width × Height Typical Capacity Application
100 × 40 mm 1150 kg @ 600mm LC Light-duty warehouse
120 × 50 mm 2450 kg @ 500mm LC Standard 2-3 ton forklifts
150 × 60 mm 3750 kg @ 600mm LC Heavy-duty 4-5 ton forklifts
150 × 75 mm 5850 kg @ 600mm LC Industrial 6+ ton forklifts
Standard vs. Metric Markets: Inch-market forks are still common in North America, with sizes like 1-1/2" × 4" (approximately 38 × 102 mm) and 2" × 6" (51 × 152 mm) .
ITA Fork Classes: Mounting Compatibility
Forks are not universal. They must match your forklift's ITA carriage class. The table below shows the relationship between fork cross-section and carriage class:
ITA Class Typical Fork Cross-Section Carriage Height Capacity Range
Class II 100 × 40 mm to 125 × 50 mm 16 inches 2,200 - 5,500 lbs
Class III 125 × 50 mm to 150 × 60 mm 20 inches 5,500 - 11,000 lbs
Class IV 150 × 60 mm to 150 × 75 mm 25 inches 11,000 - 17,600 lbs
Class V 150 × 75 mm to 200 × 90 mm 28.66 inches 17,600 - 24,200 lbs
Fork Construction and Materials
Steel Grade: Forks are typically forged from high-strength alloy steels like 4140, 4340, or 8620. These chrome-moly steels provide the necessary tensile strength and toughness to withstand shock loads without cracking .
Manufacturing Advances: Modern forks may use cold-rolled or extruded steel with a single longitudinal weldment or no weldments at all. This allows thinner sidewalls (4.5 mm vs. conventional 6.0 mm) while maintaining or improving strength and reducing weight .
Safety Factor: ANSI/ITSDF standards require a 3:1 safety factor. A fork rated for 5,000 lbs must withstand 15,000 lbs without failure.
Critical Wear Points and Inspection
The heel (the curved area where the horizontal blade meets the vertical shank) is the highest-stress point on any fork . This is where cracks most often develop and where wear is most critical.
Inspection Requirements:
Forks must be inspected at least every 12 months
Replace when heel wear exceeds 10% of original thickness
Look for cracks, bends, or twisted shanks
Check top hooks for wear (they secure the fork to the carriage)
Out-of-Service Conditions:
Visible cracks at the heel or mounting hooks
Fork bent more than 3 degrees from straight
Uneven fork tips (one higher than the other)
Special Fork Types
Lumber forks have extended tines (60-96 inches) with tapered tips for inserting between stacked materials . They are reinforced to handle the torque created by long loads.
Folding forks (crane forks) are designed for truck-mounted cranes, with foldable tines for transport. They are self-balancing and can handle pallets from the long side .
Fork extensions slide over existing forks to increase length. They reduce rated capacity because they move the load center forward.
The Bottom Line
Forklift pallet forks are defined by length, cross-section (width × height), and ITA class. Always match the fork class to your carriage. Inspect the heel for wear exceeding 10% annually. Never weld or modify forks without manufacturer approval. And when replacing, always replace as a matched pair—single-fork replacement creates uneven loading and dangerous instability.