Forklift Fork Size Chart: Dimensions, Capacity & Class Guide
TL;DR
Match the fork to your truck’s ITA carriage class and capacity first, then pick length by pallet depth. A Class 2 truck (2,000-5,500 lb) takes a 1.5×4 in section fork; a Class 4 (11,000-17,500 lb) takes 2.5×6 in. Always confirm rated capacity at your actual load center, the distance from the fork face to the load’s center of gravity, not just the nameplate.
Abstract
A forklift fork is defined by three numbers you can read off the heel stamp: section size (thickness by width), length, and rated capacity at load center. This forklift fork size chart turns those three numbers into a selection table so you spec the right fork for your truck and pallet, without hunting across five supplier pages.
Key Takeaways
- Fork size = section (thickness x width) + length + ITA class, all stamped on the heel
- Capacity derates as load center moves past 24 in: 5,000 lb @ 24 in drops to 3,333 lb @ 36 in
- ITA Class 1-5 set both carriage height and the fork’s capacity band
- Metric sections (35×100, 45×122, 75×150 mm) map to the same ITA classes
- 42CrMo / 4140 forks hold up better in cold storage than 40Cr / 5140
- Hook-on forks (ISO 2328) fit ITA carriages; pin/shaft forks (ISO 2331) fit smaller trucks
Table of Contents
- Abstract
- Key Takeaways
- Why the fork size stamp matters before you order
- How to read a fork: the three dimensions that define it
- ITA fork classes 1-5 and what they mean for your truck
- Fork size chart by capacity: section, length, and load mark
- Load center derating: why capacity drops when you carry wide
- Hook-on vs pin-mount forks, and the ISO standards behind them
- Fork material grades: what the steel number means for you
- Special forks: sleeve, port, and mining types
- How to choose: a 5-step fork selection checklist
- Frequently asked questions
- Glossary
- Further Reading
- Conclusion
- References
Why the fork size stamp matters before you order
A fork is fully defined by three numbers stamped on the heel: section size (thickness × width), blade length, and rated capacity at a stated load center. Every forklift fork size chart reads the same three figures. Read them before you quote. A mismatched fork either derates your lift or will not seat on the carriage.
Three numbers on the heel
The three figures are stamped into the vertical shank, the heel section that sits against the carriage. The load marking lists the manufacturer, the individual fork capacity in kilograms, and the rated load center in millimeters, along with a serial number.
Load center is where the two conventions diverge, and this is where buyers misquote. North American forks are rated at a 24 in (610 mm) load center, while ISO and European forks are rated at 500 mm. (Occupational Safety and Health Administration, 2023) A fork rated at 500 mm is not interchangeable with one rated at 610 mm, even if section and length match.
The section must also match your carriage. The Industrial Truck Association groups hook-type forks into Classes 1 through 5, set by carriage height and the truck’s capacity band. (Vallee, 2025) A Class 2 fork will not mount cleanly on a Class 3 carriage, so the class is part of the fit, not a detail.
The cost of a wrong fork
A fork’s capacity is only true at its stamped load center. Push the load center past 24 in (610 mm) and the fork derates, cutting the truck’s usable capacity below what the data plate promises. Read the three heel numbers before quoting so the replacement seats on the carriage and lifts at its rated figure. (Conger Industries, 2025) A common mistake is to quote the truck’s nameplate capacity as the fork’s rating. The plate rates the whole truck at its own load center, while the heel stamp rates the fork at a different reference, and the two agree only when the load center matches.
Before you order, quote the stamp, not the truck model. Transcribe the heel numbers plus the class, and match them to the replacement. That read is the difference between a fork that bolts on and lifts at its rated figure, and one that sits in the yard.
How to read a fork: the three dimensions that define it
Every fork is defined by three dimensions, and you need all three before you can order or compare. Section size, the cross-section written as thickness by width, tells you whether the fork fits the carriage. Fork length tells you whether it reaches across the pallet. Rated capacity at load center tells you whether it can safely carry the load. Get one dimension wrong and the fork either will not mount, will not reach, or will not lift.
The spec to remember is 1.5"×4"×42", a Class II fork, the most common North American fork. Its 42 in blade length converts to 1,070 mm in the metric table. (Conger Industries, 2025) Anchor on that baseline and every other length or section becomes a small, easy delta from it.
Section size (thickness x width)
Section size is the fork’s cross-section, written as thickness × width. A 1.5"×4" fork is 1.5 in thick and 4 in wide. Common thickness runs 1.5 to 2.5 in, about 35 to 75 mm, and common width runs 4 to 6 in, about 100 to 150 mm. The section must match the slot height of your carriage, so a fork that is too thick or too tall will not slide on. Quote thickness and width together, because the same thickness is sold in several widths.
ITA class maps directly to section size. A Class II fork is typically 1.5×4 in, roughly 35×100 mm to 40×100 mm. A Class IV fork is typically 2.5×6 in, roughly 60×150 mm. Heavier sections carry more load but add weight and cut into lift capacity, a trade-off worth weighing before you order, so buy the section your truck and attachment actually require.
Fork length by pallet depth
Fork length is the blade distance from the heel to the tip, and it is chosen by pallet depth, not guesswork. A fork should be at least as long as the pallet’s depth so the tips do not dig short of the far board. Standard North American stock lengths are 42, 48, 54, 60, 72, and 96 in.
In metric markets the same lengths are quoted in millimeters: 36 in = 920 mm, 42 in = 1070 mm, 48 in = 1220 mm, 54 in = 1370 mm, 60 in = 1520 mm, 66 in = 1670 mm, 72 in = 1820 mm, 79 in = 2000 mm, and 96 in = 2440 mm. Cross-check every length against the conversion table before you confirm, because a 60 in fork is not the same as a 600 mm fork.
Rated capacity and load center
Rated capacity is the load a fork is certified to carry, but only at a stated load center. North American ratings assume a 24 in load center, or 610 mm. ISO and EU ratings assume 500 mm. (Occupational Safety and Health Administration, 2023) If your load center is longer, for example a deep single load rather than a standard pallet, the safe capacity drops. Match the fork’s rating to the truck’s capacity and to your heaviest real-world load, not your lightest.
Glossary
- Section size: the fork cross-section, thickness × width in inches or millimeters.
- Fork length: the blade distance from heel to tip, chosen by pallet depth.
- Load center: the distance from the fork face to the load’s center of gravity, 24 in (610 mm) in North America and 500 mm for ISO/EU.
- Rated capacity: the load a fork is certified to carry at the standard load center.
- ITA class: a fork mounting classification that groups forks by carriage height and section size, such as Class II or Class IV.
ITA fork classes 1-5 and what they mean for your truck
The ITA class is the first filter for a fork purchase, and it is set by two fixed facts about your truck: the carriage height and the rated load. Get the class wrong and the fork will not hang on the carriage rail, even if the fork section looks close. Get the capacity band wrong and you have a fork that bolts on but is under-rated for the load. Both errors cost a return shipment and days of downtime, so the class is worth confirming before you order.
Class-to-carriage-height table
| ITA Class | Carriage height | Capacity band | Typical section |
|---|---|---|---|
| Class 1 | 13 in | < 2,000-2,200 lb | 1.25 x 3 in |
| Class 2 | 16 in | 2,000-5,500 lb | 1.5 x 4 in (also 1.75 x 4) |
| Class 3 | 20 in | 5,500-11,000 lb | 2.0 x 5 in |
| Class 4 | 25 in | 11,000-17,500 lb | 2.5 x 6 in |
| Class 5 | > 25 in (approx) | 17,500-25,000 lb | 3.0 x 7 in |
The carriage height runs 13 in for Class 1 up to 25 in and above for Class 5 (Vallee, 2025). Class 1 stays under roughly 2,000 to 2,200 lb, and Class 2 covers the 2,000 to 5,500 lb band that dominates general warehousing (Vallee, 2025). Class 3 spans 5,500 to 11,000 lb, Class 4 11,000 to 17,500 lb, and Class 5 17,500 to 25,000 lb (Vallee, 2025).
Matching class to truck capacity
Match the carriage height first. The carriage is the fixed dimension on the truck, and it decides the class (Vallee, 2025). Measure the carriage height on the truck, then match it to the nearest class in the table before you settle on a section. After that, check the capacity band against the truck’s rated load. The fork’s rated capacity must meet or exceed the maximum load the truck is specced to lift, or the pair is out of spec (Vallee, 2025).
Class 2 versus Class 3 is the comparison buyers search for most. Class 2 is a 16 in carriage rated for 2,000 to 5,500 lb with a typical 1.5 x 4 in section. Class 3 is a 20 in carriage rated for 5,500 to 11,000 lb with a 2.0 x 5 in section (Vallee, 2025). A truck at 6,000 lb of capacity lands in Class 3, not Class 2, because the band, not the section, sets the class.
The two checks do not trade off against each other. The carriage height sets the class, and the capacity band then selects the fork within that class (Vallee, 2025). A Class 3 fork on a 3,000 lb truck will not seat on the 16 in rail in the first place, and a Class 2 fork on a 7,000 lb truck would fit the rail but is under-rated for the load (Vallee, 2025). The section dimension alone does not tell you which fork to buy.
Confirm both figures against the truck’s data plate before you quote a supplier. The rated capacity is stamped on the plate, and the carriage height is measured directly on the mast. A fork sized from the wrong plate entry repeats the same class error downstream, so the measurement is worth the extra minute.
Class 2 vs Class 3 in one line: Class 2 fits a 16 in carriage and carries 2,000 to 5,500 lb on a 1.5 x 4 in section; Class 3 fits a 20 in carriage and carries 5,500 to 11,000 lb on a 2.0 x 5 in section (Vallee, 2025). Match the carriage height first, then the load rating.
Most common wrong choice: A Class 3 fork on a Class 2 truck. The carriage height is 20 in versus 16 in, so the top hook and lower pin spacing will not line up on the rail, and the fork will not seat even though the section looks roughly the same.
Talk to the factory
Reading the heel stamp gives you the three numbers that define a replacement fork, section, length, and rated capacity at load center, and those are exactly what a sourcing team needs to quote one that seats on your carriage. Transcribe them along with your truck’s carriage height, and we will match the ITA class, section, and load mark against 14 major brands before you place the order. Get your fork quote
Fork size chart by capacity: section, length, and load mark
Fork selection for a buyer starts with two numbers: the rated capacity of the truck and the load center at which you actually lift. Every fork carries a load mark that ties those two together, and the forklift fork size chart below maps tonnage to section, load mark, and available length so you can match a fork to your pallet and rack setup without guessing. We compiled this chart from our own forklift product catalog and cross-checked every section and load mark against the ITA carriage classes and ISO 2328 mounting dimensions, so the figures trace to the same data we quote on actual orders. It covers 16 distinct section sizes across 18 table rows, spanning the 1.0T to 8.0T range.
Standard fork table (1.0T to 8.0T)
| Tonnage | Section (mm) | Load mark | Lengths (in) |
|---|---|---|---|
| 1.0T | 32×100 | LT500×500 | 36, 42, 48, 54, 60 |
| 1.5-1.8T | 35×100 | LT900×500 | 36, 42, 48, 54, 60, 66, 72 |
| 2.0T | 40×100 | LT1000×500 | 36, 42, 48, 54, 60, 66, 72 |
| 2.5T | 40×122 | LT1250×500 | 42, 48, 54, 60, 66, 72 |
| 2.5T | 45×100 | LT1250×500 | 42, 48, 54, 60, 66, 72 |
| 3.0T | 45×122 | LT1500×500 | 42, 48, 54, 60, 66, 72, 79, 96 |
| 3.5-4T | 50×122 | LT2000×500 | 42, 48, 54, 60, 66, 72, 79, 96 |
| 4.5T | 50×150 | LT2500×500 | 42, 48, 54, 60, 66, 72, 79, 96 |
| 5.0T | 50×150 | LT2500×600 | 48, 54, 60, 66, 72, 77.5, 79, 83.5, 87.5, 89.5, 96 |
| 5.0T | 55×150 | LT2500×600 | 83.5, 87.5, 89.5, 96 |
| 6.0T | 60×150 | LT3000×600 | 48, 54, 60, 66, 72, 77.5, 79 |
| 6.0T | 65×150 | LT3000×600 | 83.5, 87.5, 89.5, 96 |
| 7.0T | 65×150 | LT3500×600 | 48, 54, 60, 66, 72, 77.5, 79 |
| 7.0T | 70×150 | LT3500×600 | 83.5, 87.5, 89.5, 96 |
| 8.0T | 75×150 | LT4000×600 | 48, 54, 60, 66, 72, 77.5, 79 |
| 8.0T | 80×150 | LT4000×600 | 83.5, 87.5, 89.5, 96 |
| 8.0T | 70×170 | LT4000×600 | 48, 54, 60, 66, 72, 77.5, 79 |
| 8.0T | 75×170 | LT4000×600 | 83.5, 87.5, 89.5, 96 |
Read a load mark left to right. The first number after LT is the rated load per fork in kilograms, and the second is the load center distance in millimeters. LT1500×500 therefore means each fork is rated for 1500 kg at a 500 mm load center.
One tonnage can take more than one section. At 8.0T the standard table lists 75×150, 80×150, 70×170, and 75×170, and at 5.0T it lists both 50×150 and 55×150. The thicker sections serve longer forks and larger load centers. Among the 8.0T options, the 80×150 and 75×170 bars cover the long 83.5 to 96 inch lengths, while the 70×170 bar tops out at 79 inches. A buyer who stacks deep loads or uses a spread beam should favour the taller section.
Metric and inch length conversion
Fork lengths are quoted in inches. Convert to millimeters to confirm clearance against pallet depth and rack uprights, since a fork that is too long can push through the far side of a pallet or collide with the upright behind it. The common increments are:
- 36 in = 920 mm
- 42 in = 1070 mm
- 48 in = 1220 mm
- 54 in = 1370 mm
- 60 in = 1520 mm
- 66 in = 1670 mm
- 72 in = 1820 mm
- 77.5 in = 1970 mm
- 79 in = 2000 mm
- 83.5 in = 2120 mm
- 87.5 in = 2220 mm
- 89.5 in = 2270 mm
- 96 in = 2440 mm
A fork’s load mark is the answer to how much it safely lifts. LT1500×500 rates each fork at 1500 kg with the load centered 500 mm from the heel, while LT4000×600 rates each fork at 4000 kg at a 600 mm load center. Match the mark, not just the truck tonnage, when you buy.
Load center derating: why capacity drops when you carry wide
A fork’s rated capacity is tied to one load center. The moment your pallet pushes the load farther from the heel, the effective capacity drops, and a forklift fork rated 5,000 lb at 24 in is no longer a 5,000 lb fork at 36 in.
The 24-inch standard
Load center is the horizontal distance from the fork face to the load’s center of gravity. North American trucks rate capacity at a 24 in load center (610 mm), roughly half the depth of a standard 48 in pallet, while ISO and EU trucks rate at 500 mm (Occupational Safety and Health Administration, 2023). A deeper or wider pallet moves that center of gravity farther from the carriage, lengthening the lever arm acting on the fork and cutting what it can safely hold (Linde Material Handling, 2024). The physics is a simple moment: the fork’s bending load equals weight times that distance, so extending the center of gravity even a few inches multiplies the stress at the heel. Counter to what most buyers expect, longer forks do not add capacity. They only reach the load, and the rating still assumes the 24 in or 500 mm reference, so a deeper pallet lowers the safe lift instead of raising it.
Calculating your real capacity
The derating formula is:
New capacity = Rated capacity x (Rated load center / Actual load center)
Metric example: a 2,500 kg fork rated at 500 mm, carrying at a 600 mm load center, becomes 2,500 x (500 / 600) = 2,083 kg, a drop of roughly 17% (Interlake Mecalux, 2024).
Imperial example: a 5,000 lb fork rated at 24 in, carrying a 72 in deep pallet at a 36 in load center, becomes 5,000 x (24 / 36) = 3,333 lb (Interlake Mecalux, 2024).
| Rated load center | Actual load center | Effective capacity |
|---|---|---|
| 24 in (5,000 lb rating) | 24 in | 5,000 lb |
| 24 in (5,000 lb rating) | 36 in | 3,333 lb (Interlake Mecalux, 2024) |
| 500 mm (2,500 kg rating) | 500 mm | 2,500 kg |
| 500 mm (2,500 kg rating) | 600 mm | 2,083 kg (Interlake Mecalux, 2024) |
Answer first: capacity scales by the ratio of rated to actual load center, so a 5,000 lb fork rated at 24 in derates to 3,333 lb at 36 in (Interlake Mecalux, 2024), and a 2,500 kg rating at 500 mm drops to 2,083 kg at 600 mm, a 17% loss (Interlake Mecalux, 2024).
When you spec forks, substitute your actual load center into the formula instead of quoting the nameplate rating (Linde Material Handling, 2024). Two trucks stamped with the same capacity are not equivalent if one handles 48 in pallets and the other handles 40 in pallets, because the 40 in operation is actually lifting closer to its rating. Ignoring this is how a truck that reads "5,000 lb" ends up tipping or dropping a load, since the nameplate never knew your pallet depth.
By the Numbers
- 17% capacity drop moving a 500 mm rating to a 600 mm load center (Interlake Mecalux, 2024)
- 24 in North American standard load center (610 mm) (Occupational Safety and Health Administration, 2023)
- 3,333 lb effective capacity of a 5,000 lb rating at 36 in (Interlake Mecalux, 2024)
- 500 mm ISO/EU standard load center (Occupational Safety and Health Administration, 2023)
Hook-on vs pin-mount forks, and the ISO standards behind them
Before you quote a fork order, confirm which mounting system the lift truck actually uses. There are two, and they are not interchangeable. (International Organization for Standardization, 2011)
The quick answer: ISO 2328:2011 covers hook-on forks and the matching carriage mounting dimensions, rated to 10,999 kg across five classes, each in an A and B version. Pin or shaft forks fall under ISO 2331; ISO 2329 sets fork arm section dimensions; ISO 2330 sets inspection and technical specifications. (International Organization for Standardization, 2011)
ISO 2328 hook mounting
Hook-on forks (also called clip forks) mount onto an ITA carriage rail: a top hook hangs on the rail and a lower pin locks the fork in place. (International Organization for Standardization, 2011) The fork’s class is set by carriage height: Classes 1 through 5 correspond to 13, 16, 20, 25 and over-25 inch rails. (International Organization for Standardization, 2011) ISO 2328:2011 covers hook-on forks and the carriage mounting dimensions, rated to 10,999 kg, and defines five classes, each in an A and a B version that differ in lower-hook ground clearance. (International Organization for Standardization, 2011) If the supplier cannot state the carriage class, stop the order.
ISO 2331 pin/shaft type
Pin (shaft) forks mount on a round shaft and are the standard fitment on small-wheel and rough-terrain forklifts. (International Organization for Standardization, 2011) ISO 2331 governs this pin/shaft type. A hook-on fork will not seat on a pin-mount machine, and a shaft fork will not fit a rail carriage, so confirm the type before you order. (International Organization for Standardization, 2011)
ISO 2329 and 2330 specs
ISO 2329 defines fork arm section dimensions, and ISO 2330 defines the technical specifications and inspection requirements for the fork arm. (International Organization for Standardization, 2011) For practical purposes, manufacturing and mounting both trace to ISO 2328, while inspection falls under ISO 2330. (International Organization for Standardization, 2011) Every fork must carry a load mark on one face of the vertical section, showing the manufacturer, the rated capacity per fork in kg times the rated load center distance in mm, and a production serial in year/month format. (International Organization for Standardization, 2011) That mark is what you check against your truck’s rating plate. At the weld end, a reputable maker uses 20Cr for the hook and 20# steel for the sleeve, welds with high-quality wire under Ar+CO2 shielding gas, and runs 100% penetration testing on the bent zone.
Bottom line: a compliant fork is traceable. Its mounting standard, section dimensions, inspection rules and stamped load mark should all line up, or you are buying on trust.
Ask your supplier: hook-on or pin-shaft? Which ISO standard does it meet, and what is your carriage height?
Fork material grades: what the steel number means for you
Fork suppliers quote steel in grades that read like code: 40Cr, 42CrMo, 15B37. The leading number is a carbon target, 40 means about 0.40% carbon, and the trailing letters flag alloying elements, Cr for chromium, Mo for molybdenum, B for boron. Matching that recipe to your duty conditions is what separates a fork that lasts from one that fails early.
A fork is a medium-carbon, quenched and tempered alloy steel. The two grades a buyer sees most often are 40Cr (≈5140) and 42CrMo (≈4140).
40Cr vs 42CrMo
40Cr (≈5140) is the general-purpose grade. It carries 0.38-0.45% carbon and 0.90-1.20% chromium, giving a yield strength of ≥785 MPa and a tensile strength of ≥981 MPa. For standard pallet handling it is sufficient. 42CrMo (≈4140) is the step up for heavy or high-cycle duty, with yield ≥932 MPa and tensile ≥1079 MPa, the highest of any grade in this set. Specify it when loads run near the fork’s rated capacity or cycle counts are high. 35CrMo splits the difference at yield ≥834 MPa and tensile ≥981 MPa for buyers who want molybdenum without the full step to 42CrMo.
| Grade | C (%) | Cr (%) | Mo (%) | Yield (MPa) | Tensile (MPa) |
|---|---|---|---|---|---|
| 40Cr | 0.38-0.45 | 0.90-1.20 | – | ≥785 | ≥981 |
| 42CrMo | 0.38-0.45 | 0.90-1.20 | 0.15-0.25 | ≥932 | ≥1079 |
| 35CrMo | 0.32-0.40 | 0.40-0.70 | 0.15-0.25 | ≥834 | ≥981 |
| 15B37 | 0.30-0.35 | 1.25-1.50 | 0.30-0.60 | ≥784 | ≥931 |
| 33MnCrTiB | 0.30-0.35 | 0.37-0.45 | 0.20-0.40 | ≥784 | ≥931 |
Boron-carbon grades
15B37 and 33MnCrTiB use boron (the "B" in the name) plus titanium instead of heavier chromium. Their yield ≥784 MPa and tensile ≥931 MPa sit below the chromium grades, but their job is not peak strength, it is toughness at low temperature.
Cold-storage considerations
Cold-storage and freezer duty shift the failure mode from bending to brittle fracture, so the deciding number becomes impact energy rather than tensile strength. Every grade in this set holds ≥27J at -20℃ (C-V), and surface hardness HB285-363 is consistent across the range. Boron-carbon grades are designed for low-temperature toughness, which is why they appear in cold-storage and food-handling applications. For freezer rooms, confirm the impact value at your lowest operating temperature rather than the room-temperature tensile figure.
One more point for the quote stage: the grade refers to the load-bearing blade. Fork hooks are typically 20Cr and sleeves 20#, low-carbon steels, so confirm which part a supplier’s grade actually covers.
Answer-first: "What material are your forks made of?" Medium-carbon, quenched and tempered alloy steel, most commonly 40Cr (≈5140) for general duty or 42CrMo (≈4140) for heavy load, with yield strength from ≥784 MPa up to ≥932 MPa and tensile strength from ≥931 MPa up to ≥1079 MPa.
Special forks: sleeve, port, and mining types
Standard hook forks do not cover every load. For a special application, quote the fork by section, blade length, and rated capacity at a stated load center. Sleeve forks derate sharply as load center extends, while port and mining forks use thick 100 to 150 mm sections to carry 8 to 17.5 tonnes.
Sleeve fork load table
Sleeve forks slip over the truck’s existing forks or tines to add reach or support a wider footprint without replacing the fork. The cost is capacity. Because the load center sits farther from the heel, the lever arm grows and the rated figure falls off quickly. A 75 × 150 mm sleeve fork is rated 11,700 kg at a 600 mm load center but only 5,850 kg at 1,200 mm, exactly half.
Capacity per pair, in kilograms, at three load centers:
| Section (mm) | @600 mm | @900 mm | @1,200 mm |
|---|---|---|---|
| 35×100 | 1,700 | 1,150 | 850 |
| 40×100 | 2,500 | 1,650 | 1,250 |
| 45×122 | 3,400 | 2,250 | 1,700 |
| 50×122 | 4,200 | 2,850 | 2,100 |
| 50×150 | 5,200 | 3,450 | 2,600 |
| 60×150 | 7,500 | 5,000 | 3,750 |
| 70×150 | 10,200 | 6,800 | 5,100 |
| 75×150 | 11,700 | 7,800 | 5,850 |
| 75×200 | 15,600 | 10,400 | 7,800 |
The pattern holds across every section: moving the load center from 600 to 1,200 mm halves capacity. A buyer who lifts long or tall loads must specify the sleeve fork at the load center the job actually uses, not the headline 600 mm figure.
Port and mining forks
Port forks carry container and break-bulk lifts in the 8 to 17.5 tonne range. Sections run from 100 × 200 mm up to 125 × 300 mm, blades are 2,400 to 2,800 mm long, and the load marking states the rating at a 1,200 mm load center, for example LT8000 × 1200. When quoting, transcribe that marking in full rather than the section alone.
Mining forks are the opposite of port forks: shorter and thicker, built to survive rock and broken ground rather than to reach far. Sections run up to 150 × 350 mm in blades 1,400 to 1,900 mm long. Beyond these, the special range covers coil forks for steel rolls, folding forks, and attachments such as side shifters and rotators, each specified to the carriage and duty cycle of the truck.
How to choose: a 5-step fork selection checklist
Choosing a fork is a five-check sequence, not a single quote. Run the checks in order and the section, length, material and mounting all resolve against data you can read off the truck and the pallet.
The short version: start with the carriage height, which sets the ISO 2328 class, and finish with the stamped load mark. Classes 1 through 5 map to 13, 16, 20, 25 and over-25 in rails, and capacity moves with load center: New = Rated × (Rated LC / Actual LC). (International Organization for Standardization, 2011)
Step 1: read your carriage
Carriage height sets the fork class. On an ITA hook-on carriage, a 13 in rail is Class 1, 16 in is Class 2, 20 in is Class 3, 25 in is Class 4, and anything over 25 in is roughly Class 5. (Vallee, 2025) The class is a fit dimension, not a preference, so measure the rail before you quote a fork. (Vallee, 2025)
Step 2: confirm capacity
Match the fork to the truck’s rated tonnage band, then correct it for how you actually lift. Class 1 covers loads under 2,200 lb, Class 2 spans 2,000 to 5,500 lb, Class 3 spans 5,500 to 11,000 lb, Class 4 spans 11,000 to 17,500 lb, and Class 5 spans 17,500 to 25,000 lb. (Vallee, 2025) When your load center is not the rated 24 in (610 mm), recalculate: New = Rated × (Rated LC / Actual LC). (Linde Material Handling, 2024) A fork rated at 500 mm is not interchangeable with one rated at 610 mm. (Occupational Safety and Health Administration, 2023)
Step 3: pick length
Length follows pallet depth. The common conversions are 42 in = 1070 mm, 48 in = 1220 mm, 54 in = 1370 mm, 60 in = 1520 mm, 72 in = 1820 mm, and 96 in = 2440 mm. Choose a blade slightly shorter than the pallet depth. A fork that runs long pushes through the far side of the pallet or strikes the rack upright behind it.
Step 4: choose material
Material is set by duty. 40Cr (about 5140) covers general service. Cold storage, low temperature and heavy duty call for 42CrMo (about 4140) or a boron steel such as 15B37 or 33MnCrTiB. Check the impact figure: the fork should hold at least 27 J at -20 ℃.
Step 5: verify standards
Confirm the mounting standard and the stamped mark. Hook-on forks trace to ISO 2328, and pin or shaft forks trace to ISO 2331. (International Organization for Standardization, 2011) The load mark must carry the manufacturer, the per-fork rated load in kilograms, the rated load center in millimeters, and a production serial. (Conger Industries, 2025) A fork with no legible mark is buying on trust.
Browse our fork range, from standard forks through sleeves, port and mining models: View forklift forks catalog
Selection checklist
- Check 1: Read the carriage height and confirm the ITA class (13, 16, 20, 25, or over 25 in)
- Check 2: Match the fork to the truck’s tonnage band and recalculate for the actual load center
- Check 3: Choose a blade length slightly shorter than the pallet depth in millimeters
- Check 4: Pick 40Cr for general duty, or 42CrMo and boron steel for cold and heavy work
- Check 5: Confirm ISO 2328 or ISO 2331 and read the load mark on the shank
Frequently asked questions
How do I know my fork size?
Read the load marking stamped into the side of the vertical section of the fork. It carries the manufacturer name, the individual rated capacity in kilograms, the rated load center in millimeters, and a serial number. Before you order a replacement, confirm three figures: the section as thickness by width, the overall fork length, and the rated capacity at its stated load center.
Are all forklift forks the same size?
No. Forklift forks follow ITA classes 1 through 5, each matched to a specific carriage height and capacity band, so dimensions shift between classes. Class 2 commonly uses a 1.5 × 4 in section, Class 3 a 2.0 × 5 in, and Class 4 a 2.5 × 6 in. Lengths run from 36 to 96 in, meaning two forks in the same class can still differ in length.
How do you measure forklift forks?
Take three measurements. Measure the section as thickness by width, then the length from the tip of the horizontal arm to the back of the vertical shank, then check the rated capacity at its load center. North American forks are rated at a 24 in (610 mm) load center, so confirm the center your supplier used before comparing quotes.
What is the standard load center for most forklifts?
Most North American forklifts use a 24 in (610 mm) load center. ISO and EU equipment is typically rated at a 500 mm load center. This matters because the load center directly changes rated capacity: a fork rated at 24 in will carry less weight when the load sits at a longer center.
What are the specifications for Class 2 forklift forks?
Class 2 forks fit a 16 in carriage height and sit in a 2,000 to 5,500 lb capacity band. The typical section is 1.5 × 4 in, though 1.75 × 4 in is also used. Common lengths are 42, 48, 54, 60, 72, and 96 in, so specify carriage height and length together when ordering.
What is the difference between class 2 and class 3 forks?
Carriage height is the main split: 16 in for Class 2 versus 20 in for Class 3. Capacity bands also differ, 2,000 to 5,500 lb versus 5,500 to 11,000 lb. Sections step up from 1.5 × 4 in to 2.0 × 5 in, so Class 3 forks are thicker, taller, and rated for heavier trucks.
Are forklift forks universal?
No. Hook-type forks built to ISO 2328 mount on ITA carriages, and the class is set by carriage height, so Class 2 and Class 3 forks are not interchangeable. Pin-type forks to ISO 2331 are used on small and rough-terrain trucks instead. Order the wrong class and the hook will not seat on your carriage.
What material are forklift forks made from?
Forks are made from medium carbon alloy steel, normally quenched and tempered. Common grades are 40Cr (roughly AISI 5140), 42CrMo (roughly AISI 4140), and the boron steels 15B37 and 33MnCrTiB. Hooks use 20Cr and sleeves use 20#. Heat-treated 42CrMo reaches a yield strength of at least 932 MPa and a tensile strength of at least 1,079 MPa.
Further Reading
If you are speccing more than just the forks, these companion guides walk through the rest of the forklift parts buying decision. Start with How to Source Forklift Parts Correctly: A Complete Buyer Guide for the end-to-end procurement workflow, then compare OEM vs Aftermarket Forklift Parts to decide your sourcing tier. When you are ready to shop, browse the full forklift fork catalog for standard, sleeve, port, and mining sections.
Conclusion
Buying a fork comes down to three numbers that you must get from the truck before you quote: the ITA class from the carriage height, the section size, and the length, plus the rated capacity at its load center. In practice, that means reading the load marking stamped on the existing fork’s heel, matching the class to the carriage, and then confirming the section with the supplier, because a Class 2 hook will not seat on a Class 3 carriage no matter how good the price is. The derating rule matters more than most buyers expect, so run your actual pallet depth through the ratio, rated capacity x (rated load center / actual load center), before you assume the nameplate figure still applies. Material choice narrows itself: 40Cr covers general duty, 42CrMo and the boron grades step up for cold storage and heavy or high-cycle work, and the impact value at -20 C is the number to check for freezer rooms. Standard hook forks handle most loads; sleeve, port, and mining forks are the exception, so confirm the section and blade length when you are speccing those. Get the class, the section, and the load center right on the quote, and the rest of the installation is routine.
References
- International Organization for Standardization. (2011). ISO 2328:2011 Fork-lift trucks. Hook-on type fork arms and fork arm carriages. Mounting dimensions. https://www.iso.org/standard/51106.html
- Occupational Safety and Health Administration. (2023). Load handling: Load composition. U.S. Department of Labor. https://www.osha.gov/etools/powered-industrial-trucks/load-handling/load-composition
- Shanghai HYTGER Industry & Trade Co., Ltd. (2026). Forklift fork product specification catalog [Datasheet].
- Conger Industries. (2025). Forklift forks. https://www.conger.com/forklift-forks/
- Vallee. (2025). Understanding forklift fork classes. https://vallee.ca/en/understanding-forklift-fork-classes/
- Linde Material Handling. (2024). Forklift capacity and load center: Understanding the basics. https://www.lindemhe.com/blog/forklift-capacity-and-load-center-understanding-the-basics/
- Interlake Mecalux. (2024). Forklift capacity chart. https://www.interlakemecalux.com/blog/forklift-capacity-chart
Last reviewed and updated: August 2026. Author: Kingstream team. For tailored guidance, contact our team.