What is a Class 6 forklift?: Applications, Selection Criteria, and Practical Guidance

A Class 6 forklift is a tow tractor. In the seven-class powered industrial truck system used by OSHA and the Industrial Truck Association, Class VI covers electric and internal combustion engine tractors — machines built to pull loads mounted on trailers, carts, or dollies rather than lift them. You have seen them at airports pulling long baggage cart trains, in distribution centers moving roll containers between docks, and on factory floors towing rows of parts carts to assembly stations.

The quickest way to understand a Class 6 forklift is to compare it to a standard counterbalance forklift. A Class I or Class V forklift lifts one pallet, carries it a short distance, and sets it on a rack or trailer. Its productive radius is usually a few hundred feet, and its payload is capped by what the forks can physically carry. A Class VI tractor works on different logic: it attaches to a hitch, pulls a train of carts that can weigh several times the tractor's own weight, and runs hundreds or thousands of feet on a regular route. It never lifts the load off the floor. That is not a limitation of the design; it is a deliberate efficiency strategy for horizontal material movement.

For buyers accustomed to comparing mast heights and lifting capacities, this shift matters. A Class 6 truck is selected not by how much it can lift but by how much it can pull, how far, and for how many hours. That core metric, drawbar pull, drives every other specification on the machine.

Where Class 6 Sits in the Seven-Class System

OSHA classifies powered industrial trucks into seven categories together with the Industrial Truck Association. The grouping is based on four factors: power source, tire type, operator position, and intended application. The seven classes are:

• Class I — Electric motor rider trucks, including three-wheel and four-wheel counterbalance forklifts
• Class II — Electric motor narrow aisle trucks, including reach trucks, order pickers, and turret trucks
• Class III — Electric motor hand trucks and hand/rider trucks, including walkie pallet jacks and stackers
• Class IV — Internal combustion engine trucks with cushion (solid) tires
• Class V — Internal combustion engine trucks with pneumatic (air-filled) tires
• Class VI — Electric and internal combustion engine tractors, commonly called tow tractors or tuggers
• Class VII — Rough terrain forklift trucks

Class VI is unusual because it is the only class in which the primary task is towing. It also spans two power sources: electric motor and internal combustion engine. That means a buyer choosing a Class 6 tractor makes two separate decisions — the towing specification and the energy platform. The two are related but not the same. A 48-volt electric tugger with 1,500 pounds of drawbar pull and a diesel tractor rated at the same drawbar pull can serve very different facilities.

For a complete side-by-side view of every category, including how Class VI compares with Class I, II, III, IV, V, and VII on structure, tires, and training, see our full guide to common forklift classifications and how they map to equipment types.

How a Class 6 Tow Tractor Works

A Class 6 tractor is a surprisingly simple machine under its bodywork. It has a compact chassis, a driver position, a steering axle, a drive axle, and a rear-mounted hitch. The engine or electric motor drives the wheels, and the hitch transfers pulling force to the train of trailers behind it.

The Drawbar Pull Standard

Drawbar pull is the force available at the hitch, measured in pounds or kilograms. It is the specification that determines how heavy a train the tractor can move. Two factors combine to create the total resistance the tractor must overcome: rolling resistance and grade resistance.

Rolling resistance is the friction between the trailer wheels and the floor. It is expressed as a coefficient — a fraction of the total train weight. On smooth industrial concrete with polyurethane wheels, the coefficient is usually between 0.02 and 0.03. On rough asphalt it can reach 0.05 to 0.08. Steel wheels on rails are much lower, around 0.01 to 0.02. A simple estimate of required drawbar pull uses this formula:

Required pull = train weight x rolling resistance coefficient + train weight x percent grade + acceleration force

A practical example: a distribution center moves 12 carts weighing 1,500 pounds each, so the total train weight is 18,000 pounds. The floor is smooth concrete with a 0.025 coefficient; one section has a 2 percent ramp. Floor resistance alone is 18,000 x 0.025, or 450 pounds of drawbar pull. On the ramp, grade resistance adds 18,000 x 0.02, or 360 pounds. Total steady-state pull needed is roughly 810 pounds. A compact electric tugger rated at 800 to 1,200 pounds of continuous drawbar pull can handle the route, but only with a comfortable margin for acceleration and slight variations in floor finish.

Hitch and Coupling Systems

The hitch is the mechanical interface between the tractor and the load train. Common types include pintle hitches with a lunette ring, ball hitches, drawbar eyes, and automated coupling systems used at ports. The hitch rating must match the trailer kingpin or ring, and it must be rated above the maximum train weight. A worn or mismatched hitch is a safety risk because the train can detach mid-route, especially on ramps and corners.

Steering and Maneuverability

Because a tow tractor is constantly turning with attached trailers, it uses automotive-style Ackermann steering rather than rear-wheel forklift steering. This gives the driver precise path control, which matters when a long train must track through narrow doorways. Turning radius is compact because the tractor itself is short, but the driver must account for trailer off-tracking — the rear carts of a train cut toward the inside of a turn. Aisles and corners must be wide enough for the full train, not just the tractor.

Operator Positions

Class 6 tractors come in three operator configurations. Walk-behind units are small, slow, and used for light tasks such as pulling a single cart in healthcare or retail settings. Stand-on riders suit stop-and-go routes where the driver frequently enters and exits to connect or release carts. Sit-down tractors are the standard for longer routes and heavier trains because they reduce operator fatigue over a full shift.

Class 6 Specifications at a Glance

Specifications vary by manufacturer and model, but the ranges below represent typical Class 6 equipment available on the market today. When comparing models, focus on continuous drawbar pull rather than peak pull. Continuous pull reflects sustained capability on real routes.

Towing capacity is not the same as drawbar pull. Towing capacity is the total weight of the train, while drawbar pull is the force exerted to move that train. Two tractors with identical drawbar pull can have very different towing capacity ratings depending on tire type, floor conditions, brake equipment, and maximum speed. Always confirm both ratings before specifying a machine.

Class 6 vs. Other Forklift Classes

Buyers evaluating Class 6 equipment often ask why they should choose a tow tractor over another forklift class. The comparison table below highlights the structural difference.

Notice that Class VI is the only configuration where the load stays on the floor. This is its core advantage: instead of lifting a single pallet, the tractor pulls a chain of carts, multiplying the payload per operator trip by five to ten times on long horizontal routes. That is why warehouses with large cross-dock operations, factories running just-in-time lines, and airports cannot function efficiently without them.

Where Class 6 Tow Tractors Are Used

Tow tractors appear wherever material moves horizontally in volume. The cards below summarize the most common operating environments.

Across all these industries, the common pattern is the same: a repeated horizontal route, large cumulative volume, and a load that arrives on wheels. Select a Class 6 tractor when that pattern describes your operation.

Electric vs. Internal Combustion Class 6 Tractors

Class VI is the only forklift class that gives buyers both electric and internal combustion options within the same category. The right choice depends on route length, indoor/outdoor mix, emissions limits, and charging infrastructure.

For a warehouse running two shifts in a refrigerated or clean environment, an electric tractor with lithium-ion batteries removes ventilation concerns and cuts energy cost. For a port yard moving trailers over distances of a mile or more, an internal combustion tractor avoids long charging downtime and delivers higher sustained speed. Some large fleets run electric tractors on indoor shuttle routes and keep a few IC units for yard and ramp work.

Choosing the Right Class 6 Tow Tractor

Selecting a Class 6 unit requires matching the machine to the route, not just the load. Work through these questions before contacting a supplier.

1. What is the total train weight, including cart tare weight plus the goods on every cart?
2. What floor surfaces will the train cross, and what is the condition of joints, ramps, and thresholds?
3. What is the route distance per trip, and how many trips per hour?
4. How many shifts per day will the tractor run?
5. Will the route pass through indoor areas where zero emissions are required?
6. What hitch type do the existing trailers and carts use?
7. Is charging or refueling infrastructure available at the operating location?
8. Does the operator prefer a walk-behind, stand-on, or sit-down position?

Reading the Drawbar Pull Chart

Every tow tractor manufacturer publishes a drawbar pull chart showing continuous pull at different speeds. The pull available at 3 mph is much higher than at full speed. A common error is selecting a tractor based on peak pull, then discovering that continuous pull on the actual route is insufficient. Use the calculation method above with your own train weight, surface, and grade data.

New, Used, or Rent First

For a new route or a first-time towing operation, renting a Class 6 tractor for 30 to 60 days is a practical way to validate train configuration and route times before committing capital. For established operations with predictable duty, purchasing new equipment with lithium batteries and a full warranty gives the lowest total cost over five years. For auxiliary routes, backup capacity, or seasonal peaks, a warehousing logistics solution can include used tow tractors, leased units, and hybrid new/used fleet planning. Used tow tractors retain value well because their powertrains are simple and the frame experiences lower stress than a lifting forklift of similar age.

Building a Full Material Handling System Around a Tow Tractor

A Class 6 tractor never works alone. The carts it pulls must be loaded and unloaded, inventory must be picked into the carts, and spot loads must be moved where the train cannot go. An efficient operation combines the tow tractor with pallet trucks, order pickers, and handling accessories.

At the ends of every tow route, pallet trucks handle the transfer between pallet storage and cart staging areas. A 2-ton lithium battery pallet truck gives an operator the ability to pull loads directly onto the trailers, position them, and move staged pallets without calling a counterbalance forklift. This keeps the tow tractor on its route instead of waiting for loading support.

锂电2吨电动托盘车在拖车路线的两端，这款锂电托盘车能快速完成托盘转移和装车定位，让牵引车专心跑路线，提升装卸效率。View Product →

In picking operations, order pickers assemble the carts that the tow tractor later pulls to the dock. The combination of picker and tractor divides labor correctly: the order picker travels through the racks and builds the load; the tugger moves the completed train to outbound staging. This split is standard in retail and parts distribution because it doubles the throughput of the same labor hours.

锂电0.5吨电动拣货车针对拣货作业设计，小转弯半径和电动助力转向让操作更灵活，有助于快速组装配送推车，提高拣货吞吐量。View Product →

Maintenance and spot moves also create demand for simple manual equipment. A hand pallet truck is the cheapest and most reliable backup for a Class 6 operation: it can clear a jammed cart, move a single pallet in a narrow cage aisle, and provide redundancy when powered equipment is down. Many facilities keep one at every loading dock for exactly this reason.

手动液压托盘车（1.5-3吨）作为备用设备，这款手动托盘车在动力设备故障或狭窄通道中能轻松应急，是每个装卸平台都值得配备的可靠备份。View Product →

In addition to load handling, every Class 6 fleet relies on a steady supply of spare parts and replacement components. Hitches, wheels, tires, and towing attachments wear faster than the tractor itself. A documented parts strategy — original spare parts from the tractor manufacturer or verified replacement parts — prevents avoidable downtime. Our parts catalog covers drivetrain, tire and wheel assemblies, and attachments used across tow tractors and other Class I through Class VII trucks.

Safety and Operator Training for Class 6 Trucks

Operator training is mandatory for every powered industrial truck class, and Class VI is no exception. Training must be specific to the type of equipment the operator will use; a certification for Class I counterbalance forklifts does not automatically cover a Class VI tow tractor, because the driving skills are different.

Hitch and Coupling Inspections

The most critical pre-operation check is the hitch. Confirm the coupling engages fully, the safety latch functions, and the trailer's kingpin or ring is free of cracks and wear. A trailer that detaches from the tractor on a ramp creates an uncontrolled rolling load. Establish a daily inspection sheet that includes hitch condition, brake function, tire pressure, and warning devices.

Speed and Braking with a Train

Towing multiplies stopping distance. A tractor that stops quickly when running solo can take twice as long to stop with an 18,000-pound train behind it. Site speed limits for tow routes should be set lower than standard forklift limits — commonly 5 mph indoors. Drivers must also account for the fact that trailers have no brakes on many designs; the tractor brakes carry the entire train, plus the push from any carts with defective wheels.

Cornering and Trailer Off-Tracking

Trailers follow a tighter path than the tractor through a turn. This off-tracking effect causes the rear carts to swing toward the inside of corners, and the tail of a long train can hit racking, doorframes, or pedestrians even when the tractor clears them easily. Mark tow routes with floor lines, install convex mirrors at blind corners, and train drivers to widen their turns.

Pedestrian Separation

Tow tractors operate in the same aisles as walkers, pickers, and other equipment. Use designated tow routes, audible warning devices, and spotter procedures when crossing pedestrian zones. Some facilities adopt a rule that the train never enters a pedestrian aisle until a spotter confirms the path is clear, particularly in warehouses with row-end doors.

Load Securement

Cart contents can shift during towing, especially on ramps and rough surfaces. Make sure the carts themselves are stable when loaded, that palletized loads on carts are stretch-wrapped or restrained, and that no cart is overloaded beyond its rated capacity. The tractor can pull far more than a badly loaded cart can carry safely.

Maintenance and Lifecycle Costs

Class 6 tractors are simpler than lifting forklifts because they have no mast, no hydraulic lifting system, and no fork carriage. This simplicity reduces some maintenance costs but introduces others.

Electric Tractor Maintenance

For electric models, battery care is the main recurring task. Lead-acid batteries need water checks, equalization charges, and connector maintenance. Lithium batteries reduce daily maintenance but require a battery management system matched to the charger. Drive motors and controllers accumulate fewer service hours than an engine, but wheel motors on electric drive axles must be inspected for seal wear and contamination, especially in dusty operations.

IC Engine Tractor Maintenance

Internal combustion tractors follow the standard engine maintenance cycle: oil and oil filter, air filter, fuel filter, coolant, and valve adjustments at the intervals specified by the engine manufacturer. Diesel units with DPF filters require regular regeneration or cleaning when operating mostly at low speed and low load, which is common on yard shutdown routes. LPG units are generally simpler on emissions equipment but require vaporizer and pressure-regulator inspection.

Common Wear Points

Regardless of power source, tow tractors wear through tires, wheels, and hitch components. The table below summarizes typical service intervals, though actual intervals depend on duty hours.

Budget for a replacement battery or overhaul as a mid-life expense on electric models. On IC models, the equivalent mid-life event is an engine overhaul or, in some fleets, a powertrain replacement. Factoring these costs into the five-year total cost of ownership gives a more accurate comparison than the purchase price alone.

Frequently Asked Questions