Heavy Duty Anti Static Flat Casters Applied for Logistic Equipment
and Pipe Tote Cart
Types of casters
Casters comprise two major categories: a swivel caster pivots
around a kingpin, so it rotates as well as rolls, while a rigid caster has its
wheel mounted in a fixed frame, or rig, and only rolls.
This type of caster allows for movement in multiple directions.
They can have one or two sets of raceways that allow the caster to
swivel 360 degrees under a load. The different types of swivel
casters include the following:
- Locking casters: There are several devices that can be added to casters to prevent
the wheel from rotating or the swivel assembly from turning.
- Kingpin-less casters: This caster does not have a bolt and nut kingpin. The raceways are
a one piece construction forged together. This design is extremely
durable and can be used in abusive applications and shock load
applications where kingpin type casters may fail.
- Hollow Kingpin casters: This type of caster has a tubular rivet that holds the caster
together. The hole in the rivet can accept a bolt or a customized
stem for any type of mounting requirement.
- Plate casters: This is the most common type of means to mount a caster to a unit
and is sometimes called the top plate. Most mounting plates contain
four holes used to bolt the caster to the unit. Top plates are
offered with various hole patterns to match numerous types of
- Stem casters: This type caster can have various stem styles to be used to mount
the caster to a unit. Some common types of stems are threaded,
round or square with mounting holes, friction ring & expandable
This style of caster only allows forward and backward movement.
Rigid casters tend to be stronger than swivel casters. They are
rated at the same capacity as the swivel casters for safety
reasons. They can be a one piece construction or a two piece
construction that is riveted or welded.
The key dimensions to consider when determining the proper type of
caster and caster size for a particular type of equipment and
application are its overall height, swivel radius, and swivel offset (see Caster Dimensions diagram). The key elements of a caster include the following:
- Mount: Casters mount to equipment or carts in three common manners. A
caster top plate allows the caster to be bolted to the underside of
the equipment. A caster stem may screw into place or ‘snap’ into
place. Casters may also have a bracket allowing the caster to be
mounted to vertical panels.
- Swivel head: A rigid caster allows single back and forth direction. A swivel
caster allows for 360 degree directional movement. The swivel
action of a caster depends on bearings and lubrication. Bearing
designs include ball bearings and raceway bearings. Grease fittings
serve to inject grease into the axles, caster raceways and wheels.
Grease fittings may also be known as "zerks."
- Yoke: The part of a swivel or rigid caster and can be considered a
frame. The caster yoke serves to hold the wheel in place. The yoke,
working with a swivel head allows the caster wheel to operate in a
360 degree manner. The yoke is also known as the fork, rig or
- Spring mechanism: Certain casters serve a shock absorbing or vibration dampening
function so there needs to be a spring mechanism in the caster
design. The typical spring mechanism is a coiled steel spring.
There are also hydraulic and elastomeric springs.
- Wheel: Caster wheel materials include elastomers (rubber and
polyurethane), phenolic, nylons and even steel. There are numerous
grades of all of these materials. The proper wheel selection is
dependent on application factors such as floor conditions, load,
rollability, speed and climate.
- Wheel bearings: Most caster applications require the wheel to function with a
bearing. There are numerous bearing options depending on the wheel
design and the application being considered. Common bearings used
for caster wheels include: roller bearings, tapered roller
bearings, ball bearings, precision ball bearings, Delrin and self-lubricating sleeves.
- Axle bolt and nut: The axle bolt locates the wheel into the caster yoke. The nut
secures the axle to the yoke. In some applications the axle bolt
and nut may be hardened or zinc plated for corrosion resistance.
Stainless steel may occasionally be used.
Casters are available in a large selection of various rigs and
yokes, wheel materials, swivel offsets, and wheel configurations.
In many cases, it can become extremely difficult to choose the
right caster for the application. In order to help the user to
determine the right caster to use, it's important to take a couple
of factors into consideration, which include:
- Load capacity (the total load applied on the casters)
- The number of casters to be used on the equipment (usually four or
- Floor type (concrete, steel, linoleum, carpet, etc.)
- Floor condition (are there cracks, bumps, unlevel floors?)
- Environment (is the equipment operating in high temperatures, wet
or humid conditions, etc.)
- Floor cleanliness (are the floors clean or contain debris such as
metal chips, grease, gravel, etc.)
Many casters are specifically designed for each of the following
Typical caster found on an office desk chair.
Industrial and automotive
Casters can be designed to meet the ergonomic needs of an
industrial or automotive plant setting, which typically means floor
conditions can range from being relatively clean, to having some
debris. For these applications, casters can be designed using a
variety of wheel materials, including thermoplastic elastomers, polyurethane, and soft rubber wheels. Harder wheels, such as the elastomer and polyurethane can
be used on smoother concrete plant floors to give easy rolling for
plant equipment, and the softer wheels such as those made with
rubber, can be used on various floor surfaces with debris. The
increased swivel offset on many rigs can also be designed into the
caster to reduce the swiveling force of casters (the force required
to turn a caster in the direction of travel). Many industrial casters are also designed with multiple wheels to
allow for an increased load capacity to be handled by the
Multi-wheel swivel caster used in heavy industrial applications
A broad range of industrial applications require the movement of
large, heavy objects. Aerospace is one such category, in which large airframes or engine parts are moved throughout manufacturing plants. Casters
in these plants are high capacity, with load limits of several tons
each or more. The caster wheels must be robust, and are normally
forged steel, nylon, or metal with a polyurethane tread. In some cases they may be pneumatic or solid rubber, and
the casters may be multi-wheel (i.e., having two or more wheels per
Casters used in and around furnaces and ovens must withstand extreme heat. General purpose casters cannot survive excessive heat because tread materials, lubricants and other critical components can fail. For example, at 200 degrees F, common resilient tread materials
are at or above their functional temperature limits. High
temperature casters employ special lubricants and materials that
can withstand higher heat. Additionally, for very high
temperatures, special sleeve bearings may be used that have no
Casters are widely used in the medical industry for applications
such as hospital beds, equipment carts, surgical tables, and IV
poles. Medical casters must tolerate exposure to the various
cleaning and disinfectant fluids used in hospitals. Hospital beds
and stretchers are typically equipped with a central caster locking
system that allow all casters to be simultaneously locked by one
person. Medical equipment casters must often have high load
capacities, with low profiles and swivel resistance, to accommodate
high patient or equipment weight while providing ease of operation
over different floor types and through tight spaces.
Safety and reliability are paramount for casters that support
(e.g., hospital beds) patients. Consequently, medical casters are
subject to industry requirements such as ANSI, BS EN12531, and IEC 60601.
Health and safety regulations
The primary example of the benefits of using casters is to reduce
the risk of workplace injuries for its users, particularly
overexertion. Overexertion occurs when the caster being used is not suited for the
application, mainly due to the wrong wheel material or rig, causing
injury to the user.
There are many health and safety organizations that enforce and
regulate the allowable forces and noise levels that casters can
make on a plant floor, and include the Canadian Centre for Occupational Health and Safety (CCOHS), Occupational Safety and Health Administration (OSHA). For example, CCOHS recommends that the maximum horizontal
force someone should exert is 50 lbf. Liberty Mutual has also produced a Snook Table that provides the
percent population of male and female able to push at a given
horizontal force. This force can be adjusted to a safe level by providing the right
caster wheel material and rig.
To ensure the design integrity of casters, the Institute of Caster
and Wheel Manufacturers (ICWM) working in collaboration with the American National Standards Institute (ANSI) has developed the ANSI ICWM: 2012 The ICWM Performance
Standard for Casters and Wheels which is intended to provide manufacturers, specifiers and users
with a common basis for evaluating the safety, durability,
structural adequacy and technical requirements for group specific
casters and wheels.
1. We have professional engineer to do after-sale service if
2. Local service will be done by our local agent if needed.
3. OEM is welcomed or design as customer request.