Forklift Terminology

Bulk Storage

An area in a warehouse set aside for storage of multiple pallets of a given product.

Cantilever Racks

A rack system that has arms cantilevered of a vertical column and loads are placed either directly on the arms or on shelves supported by them.

Capacity

The rating given a forklift indicating the amount of weight that it will lift to a predetermined fork height at a specified load center.

Casters

Non-powered wheels containing a swivel base that allows them to turn freely.

Chassis

The entire structure of a truck including areas that house the engine or drive units.

Clamp

Bale Clamps and Paper Roll Clamps (as the name implies) are used to handle large Bales of product (cotton, etc.) or large rolls of Paper.

Control Handle

The mechanism that contains the wiring, controls and related hardware for controlling various functions of a forklift.

Counterbalance

A forklift that utilizes weight in the chassis to counterbalance the load.

Counterweight

A dead or nonworking load (usually lead or cast iron) attached to or incorporated into the rear of a counterbalanced truck, used to balance the load carried on the forks.

Cushion Tire

A solid rubber tire molded to a rim and pressed on the wheel, also called a “solid” tire, most effective on smooth and/or paved surfaces. Size is shown as diameter x tread width x rim size.
Characteristics:

• Tight turning radius
• Compact dimension
• Quiet
• Exceptional visibility
• Low or no emission

Target markets:

• Trucking and Warehousing
• Wholesale and Retail Distribution
• Machinery and Equipment
• Food and Beverage Distribution
• Chemical and Textile
• Drug Distribution and Health Care

Dockboard

A devise that acts as a bridge between the gap of a dock and the bed of a vehicle.

Drawbar pull

The pull a vehicle can exert on a load attached to is drawbar; depends on power, weight, and traction.

Fork Positioner with Sideshifter

Fork Positioners w/side shift perform the same functions as a side shift with the additional ability of moving forks closer together and further apart for different size loads.

Battery Discharge Indicator

A meter or gauge utilized on lift trucks that indicates the state of charge in the battery. Also referred to as Discharge Indicator or BDI.

Fork size

Dimensions of each fork expressed as thickness x width x length.

Fork spread

The maximum distance the forks can be positioned; as measured from the outside edge of each fork.

Free fork height

The distance from the floor to the carrying surface of the forks when the forks are at their highest position with the mast in the down position (before beginning to telescope). Can determine the ability to lift and carry loads within low overhead spaces such as containers and boxcars. This is computed by adding fork thickness to free lift.

Free lift

The vertical distance the forks can be raised before the lowered height of the mast begins to increase.

Grade clearance

The angle between the plane contacting the front tires and passing the front lower end of the mast and ground is called the “Approach angle”.

The angle between the plane contacting the rear wheels and passing the rear lower end of the forklift truck and ground is called the “Departure angle”.

The angle between the lane intersecting on the underside parts of the body where the first plane is tangent to the front tires and the second plane is tangent to the rear tires is called “Ramp brake over angle”.

Gradeability

The slope up which a rolling machine can move at a uniform speed, stated in percentage or degrees.

Head Clearance

The head clearance is the distance from the seat cushion to the bottom of the overhead guard when the operator is seated.

Head length

The distance from the rear of the truck to the vertical face of the fork. Head length plus load length equals total length of a loaded truck.

Height to top of overhead guard

The distance from the floor to the highest point on the overhead guard.

High visibility mast

Also known as see through masts or other names specific to a manufacturer. A mast designed for maximum operator visibility, usually accomplished by placing the lift cylinders to the sides.

Horsepower drawbar

The horsepower available to move a tractor and its load after deducting losses in the power train.

Horsepower indicated

The horse power developed in the cylinders, determined by the use of an indicator gauge. It does not include losses due to friction.

Horsepower shaft, flywheel, brake

Actual horsepower produced by the engine after deducting the drag of accessories.

Hydrostatic transmission

A transmission consisting of an engine driven variable displacement pump and motor providing infinitely variable speed control from zero to top speed without gears or clutches.

Inch Pound Rating

A rating given a forklift to determine what capacity load it can lift at extended load centers.

Lifting speed

The upward speed of the forks either loaded or unloaded, expressed in feet per minute (fpm).

Load Capacity

The maximum load in pounds (or kilograms) that a truck can transport and/or stack to a specified height as rated by the manufacturer. Normally stated as a given load center, 25 cm being the most common.

Load center

The horizontal distance between the front vertical face of the forks and the longitudinal midpoint of an evenly distributed load. Note as the load center shifts forward (increases) the load capacity must be de-rated (decreased).

Lowering speed

The downward speed of the forks either loaded or unloaded, expressed in feet per minute (fpm).

Manual transmission

A transmission employing gear trains and clutches engaged and manually shifted.

Maximum fork height

The ultimate surface height of the forks with the mast fully extended. Because of pallet or load overhang, stacking at precisely this height may not be possible.

Maximum fork height, rated capacity

The ultimate height of a lift before the load must be de-rated. This list height is often accomplished with other than the standard mast.

Maximum fork spread

The outside measurement of the forks when the forks are moved on the outside notches of carriage.

Maximum ground clearance

The height from the ground to the lowest point of the machine with exception of the wheels. Examples: under mast, under power unit, or under frame.

Minimum aisle, right angle stack

The smallest aisle width in which a truck can accomplish a right angle stacking procedure. Because some of a truck’s overall length (and the load itself) is ahead of the front wheels, the minimum aisle for a right angle stack need to be greater than the truck’s turning radius. Minimum aisle, right angle stack = turn radius + front overhang + load length + clearance.

Minimum fork spread

The outside measurement of the forks when the forks are move on the inside notches of carriage.

Non-marking Tires

Non-marking tires are solids but specifically designed to prevent black marks on floors. Grocery and food processing factories are required to use them. The main drawbacks of non-marking tires are that the carbon black is removed from them, which consequently shortens the life span of the tire.

Orderpicker

A forklift with an operators platform located above the forks which raises and lowers with the forks. Also referred to as a Stockpicker.

Outside turn radius

The radius of a circle with its center at the front wheel of the truck on the side of the truck towards which the truck is moving.

Overall height

The height to the top of the forklift truck. The mast overall height is classified in two categories: mast extended overall height when the forks are fully raised and mast lowered height the forks are fully lowered. The mast lowered overall height must be compared to the height of the overhead guard. This dimension is essential when judging whether or not a forklift truck will be able to pass through and entrance to a building or some structure.

Overall length (OAL)

The distance from the extreme rear of the truck to the front face of the forks.

Overall width (OAW)

The outside distance between the widest parts of the truck.

Overhead Guard

A framework fitted to a forklift located above the head of the operator to protect the operator from falling objects. Also called a Drivers Overhead Guard.

Pneumatic tires

An inflatable tire offering greater traction and cushioning (than cushion tires). Most appropriate for outdoor and rough surface areas. Size is typical shown as tread width x rim size – ply rating.

Powershift transmission

A transmission that can be shifted while transmitting full engine power to the wheels, usually teamed with a torque converter to effectively absorb drive train shock. Available in single, two speed, three speed, and four speed versions.

Rear overhang

Distance from rear axle center to rear of the truck body.

Right angle (90°) intersecting aisle

The minimum turning radius indicates the sharpness of a turn, but it does not indicate how large a space is required to make a turn. The right angle intersecting aisle is defined as the minimum width of aisle which intersects at right angles through which the forklift truck is able to pass. This is usually stated for a non-loaded forklift with the forks set at their widest position.

Right angle (90°) stacking aisle

Seat height

The height from the ground to the seat cushion when the operator is seated.

Sideshifter

Sideshifters are used to move forks from side to side. This helps position loads for placement into trucks or rack.

Solid Tires

Today the most common tire. They are the same as pneumatic, however not filled with air therefore they don’t provide a cushioning effect. They do not puncture or go flat and are long lasting. Excellent for indoor use or light outdoor use, but not for rough outdoor or uneven surfaces.

Step height

The height from the ground to the step.

Torque

The twisting force exerted by or on a shaft without reference to the speed of the shaft. Torque = H.P. x 525.

Torque converter

A hydraulic coupling that utilizes slippage to multiply torque.

Travel Speed

The maximum speed a truck will achieve in high gear either loaded or unloaded. It’s expressed in kilometer per hour.

Tread

The distance from the center line of one tire to the center line of its corresponding tire(i.e. front to front, rear to rear).

Turning radius

The turning radius or turning circle of a vehicle is the size of the smallest circular turn that the vehicle is capable of making.

Wheelbase

The distance from the front axle to the rear axle.