The Occupational Safety and Health Administration (OSHA) requires forklift operators to check their equipment before and after each use. However, many skip an important part of that process: reading and understanding the data plate.
Data plates are small and easy to overlook, so that may be one contributing factor. But even operators who take the time to read data plates don’t always understand the relationship between the numbers,
The data plate tells you information such as the machine’s rated capacity, mast type, attachments, and tires. However, this information only applies under specific conditions, like a defined load size, a set lift height, and no attachments. When any of those conditions change, so does the safe working capacity.
This post walks through every element of a standard forklift data plate so you can read one correctly, helping you stay compliant with your facility’s and OSHA’s requirements.
Note: For background on load center theory, see our forklift load center article.
Forklift Data Plate Explained: Why It’s Required
The data plate, also called the nameplate or capacity plate, is a label fixed to the forklift. Usually made of metal or some other heavy-duty material, it’s usually located on the dashboard, overhead guard upright, or instrument panel of a machine. It contains the machine’s rated specifications as configured from the factory.
OSHA 29 CFR 1910.178(e)(1) requires that a legible data plate be present on the machine at all times and that operators understand it before using the machine. This is because the plate is the only document that tells you what the machine can safely carry under its listed conditions.
A forklift without a readable data plate is a compliance violation. If the data plate is missing, damaged to the point of being unreadable, or outdated because an attachment has been added, it should be replaced or updated as soon as possible. Until then, the machine should not be operated.
How to Read a Forklift Data Plate: Elements to Know
The data plate is the forklift’s legal and technical blueprint. It lists the capacities, configurations, and limits specific to that machine.
Here are some of the major elements of a forklift data plate and how they determine safe operation:
Rated Capacity
Rated capacity is the first number most operators look at. Unfortunately, it’s also the one that’s misapplied most often.
Rated capacity is the maximum load weight the forklift can safely handle under the specific conditions stated on the plate. Those conditions include:
- A defined load center distance
- A defined lift height
- The machine in its base configuration without attachments
Change any of those conditions, and the rated capacity no longer applies.
Consider this forklift data plate example:
A plate that reads 5,000 lbs. at 24″ load center means the machine can safely carry 5,000 lbs. when the load’s center of gravity is exactly 24 inches from the face of the forks. That is a specific scenario, not a blanket weight limit.
If you carry a load with a farther center of gravity, like an offset or longer load, the actual safe working capacity decreases from the rated capacity. For instance, at 28 inches, it might derate to about 4,285 lbs. using the formula: (rated load center ÷ actual load center) × rated capacity.
This is the most common misreading of the forklift data plate: treating rated capacity as a fixed weight limit rather than a capacity tied to a defined load geometry.
How Load Center Distance Affects Capacity
Load center distance is the horizontal distance from the face of the forks to the center of gravity of the load. On a standard 48-inch-deep pallet with evenly distributed weight, the center of gravity falls at 24 inches. That’s why 24 inches is the load center used on most standard data plates.
When the load center increases, the load’s weight creates more tipping force around the front axle. This happens when the load is long or front-heavy, or when the forks are carrying an extended load. The greater distance reduces the counterbalancing effect of the machine’s own weight and lowers the safe working capacity.
Most data plates include a capacity chart showing how rated capacity decreases as load center increases:
- 24″ load center — 5,000 lbs.
- 36″ load center — 3,800 lbs.
- 48″ load center — 3,000 lbs.
If the load you’re carrying has its center of gravity further than 24 inches from the fork face, use the chart to find the correct capacity for that load center distance. Don’t just refer to the headline number at the top of the plate.
For a detailed explanation of how to calculate load center for non-standard loads, see our guide to determining the forklift load center.
Lift Height and Capacity Derating
Rated capacity on the data plate is also specific to a defined maximum lift height. As lift height increases, raising the load raises the combined center of gravity of the machine and load together. That reduces stability, so manufacturers reduce the rated capacity at greater heights.
The data plate will either state a single rated capacity at a maximum lift height, or include a capacity-at-height chart:
- At 130″ lift height — 5,000 lbs.
- At 185″ lift height — 4,500 lbs.
- At 240″ lift height — 3,800 lbs.
Operators who read only the headline capacity and ignore the height column risk carrying over-capacity loads at height. This can lead to overload incidents like tip-overs, which can be especially dangerous in high-rack environments with narrow aisles.
If you’re stacking above the base-rated lift height, check whether the plate includes a height derating chart. If it does, the lower capacity for that height is the number that applies.
Attachment Derating
A side-shifter, clamp, or other attachment adds weight to the front of the machine. It shifts the effective load center forward and reduces available counterbalance capacity. Additionally, it moves the load further from the fork heel, increasing the load center distance beyond what the base plate accounts for. This reduces safe working capacity below the original data plate rating.
This forklift data plate example illustrates the impact of an attachment on capacity:
A forklift rates at 5,000 lbs. and the load weighs 4,500 lbs. Adding a side-shifter derates the capacity to 4,200 lbs. Now the load exceeds the safe limit, creating tip risk despite the original headline number.
Major manufacturers like Toyota and Crown offer forklifts that come with attachments preinstalled at the factory. These ship with capacity data plates that reflect the attachment’s derating, listing the attachment model and reduced capacities specific to that configuration.
For rental machines with attachments already installed, always confirm the data plate shows updated specs. These plates list the attachment make, model, and reduced capacity ratings.
Never operate a forklift if the plate displays only the base configuration despite having an attachment. Instead, contact the rental company immediately so they can address the issue.
Mast Type
The data plate identifies the mast configuration installed on the machine. Common designations include:
SS (Single Stage / Simplex)
- One mast section with limited lift height and full visibility
- Typically used for loading and transport rather than high racking
2S or DS (Two Stage / Duplex)
- Two mast sections where the inner section telescopes up
- Offers a free-lift zone where the carriage rises before the mast extends
- Useful in trailers and containers with limited overhead clearance
3S or TS (Three Stage / Triplex)
- Three mast sections with maximum lift height and free lift
- The standard configuration for high-rack warehouse operations
QF (Quad)
- Four mast sections for maximum height, with a low collapsed height
Capacity derating at height is mast-specific. A triplex mast on the same base machine will have different capacity-at-height figures than a duplex mast, so the data plate must reflect the mast that’s actually installed. If a mast has been replaced or modified, the plate needs to be updated before the machine is operated.
Tire Specifications
The data plate lists the exact tire type and size for which the machine’s capacity ratings were calculated. Those ratings depend on the specific tires’ weight, dimensions, and traction characteristics.
Using different tires than specified, such as if you substitute cushion for pneumatic or vice versa, alters the center of gravity, ground clearance, and stability in ways not accounted for in the original capacity data. The tire specification is mandatory.
See our guide to indoor vs. outdoor forklift configurations for details on cushion vs. pneumatic differences.
Serial Number and Model Designation
Every data plate lists a serial number and model designation. The serial number identifies that specific machine, not just the model line. If a plate is ever damaged or needs to be replaced, the serial number is what you use to order the correct replacement from the manufacturer.
You cannot use a generic plate with approximate figures: this goes against OSHA standards, specifically 1910.178(a)(4). The replacement has to match the exact specifications of that machine.
The model designation identifies the base configuration the machine was built to. Use it to verify that an attachment capacity plate matches the correct machine or to cross-reference the manufacturer’s documentation for capacity charts not printed on the plate itself.
How to Apply the Data Plate to a Real Load
Before picking up any load that isn’t a standard 48-inch pallet at normal stacking height, follow these steps in order.
1. Determine the actual load weight
If the weight isn’t marked on the load, find out what it is before lifting. Estimating the weight of a load that’s close to the machine’s rated capacity introduces risk.
2. Calculate the Actual Load Center
Measure the load depth and divide by two for evenly distributed weight. For loads that are heavier at one end, determine where the actual center of gravity sits and compare that figure to the load center distance on the plate.
3. Check the Lift Height
If the load is going above the base rated lift height, find the height derating column on the plate and use the capacity figure that corresponds to the actual height, not the headline number.
All three variables (the load weight, load center, and lift height) have to be within the plate’s parameters for the lift to be within rated capacity. If any one of them falls outside the plate’s specifications, the load exceeds safe working capacity for that machine, regardless of what the top-line capacity figure says.
What Operators Are Required to Know
OSHA 29 CFR 1910.178(l) requires operators to be trained on truck capacities and operating limitations, which includes proper data plate interpretation. This means understanding that:
- The rated capacity applies to a specific load center distance, not to any load up to that weight.
- The lift height affects safe working capacity, and the height derating chart on the plate is not optional information.
- Attachments require an updated plate as they reduce the capacity shown on the original.
- Operating outside the plate’s parameters is an over-capacity condition regardless of how the load feels during the lift.
A forklift that tips or drops a load while within the headline capacity number is almost always a load center or lift height problem. The operator applied the right number to the wrong scenario. The data plate contains everything needed to avoid that outcome. The requirement is knowing how to read all of it, not just the top line.
Important: Data plate specifications vary by manufacturer, model, and configuration. Always refer to the specific plate on the machine being operated and consult the manufacturer’s documentation for load capacity charts not shown on the plate. For facility-specific compliance questions, consult a qualified safety professional.
Know the Plate Before You Operate Your Forklift
The data plate is a small label with a lot of information packed into it. All entries, including rated capacity, mast type, and tires, govern what the machine can safely do. Reading only the headline capacity number and ignoring the rest is how most data plate mistakes and resulting accidents happen.
BigRentz is the largest construction and industrial equipment rental platform in the U.S., with access to inventory across more than 6,000 rental partners and 14,000 locations nationwide. When you rent a forklift through BigRentz, our team can help you confirm the right machine for your application.
Browse our forklift rentals or call 855-999-LIFT to discuss your requirements.
