What Defines Caster Wheels?
Caster wheels are unpowered wheels affixed to the base of larger items and allow for easier movement and repositioning. Caster wheels are common to items like shopping carts, office chairs, hospital beds and material handling equipment.
Caster wheels come in countless types for very specific uses. However, caster wheels have many great features and advantages with regard to mobility, such as durability, as well as being weather, water, and corrosion resistant.
The right caster wheel depends on the type of terrain and the weight of the load. Heavier loads require more durable wheels and larger objects may require multiple casters to help distribute the weight.
Manufacturing Process of Caster Wheels
This part explains the manufacturing processes essential for making caster wheels.
Metal Plate Cutting Procedure
The first step in making caster wheels is to cut the top plate, which affixes the caster to various items, like industrial carts. Cutting is achieved by slicing through a thick sheet of steel using a CNC machine.
This type of CNC uses a mixture of oxygen and electrical current to create plasma. Plasma cutting is a thermal cutting process that melts through met by using an ionized gas. It achieves high precision and speed when making cuts in both thick plates and thin sheets of metal.
Next, the fork must be cut, which is the piece that supports the weight of either side of the wheel axle. Forks are made of a steel coil that is thinner and more malleable than regular steel. The coil is rolled up and fed into a punch press to be shaped into yokes.
The yokes are press-formed into shape with a round hole and the groove is made around its centre hole. The centre hole is then filled with ball bearings that allow for swivelling motion.
A steel retainer holds the ball bearings. Additional bearings are added to the grooves of the steel cap and all the pieces are assembled using a punch press. The steel cap is held to the retainer of the yoke, trapping the bearings inside cut from the other side of the yoke.
The top plate is then riveted onto the side of the handmade yoke and finally the last steel seal is pressed on using a pneumatic press.
Extrusion of Rubber or Nylon Materials
Finally, we move to the next part of caster wheels, which is extruding wheels. In an injection molding press, the nylon inserts are placed into a cavity where the neoprene rubber is melted and injected into the molds.
After the rubbering molds have cooled, the end results are solid rubber-edged wheels that will absorb shock, deaden noise, and be gentler to the floor.
Larger wheels require a different molding press based on their size, but the molding process remains the same. In general, the larger presses will produce one wheel per cycle.
Wheels are allowed to cool for about two and half hours after molding. The mold has two parts in which the combination creates one single wheel. Once removed from the press the rubber must be shaved to create a flat surface.
Assembly Process of Caster Wheel Components
The two-piece bearing is press fit into the wheel for security. There are steel guides on both sides to shield the structure from debris and stabilize the wheel assembly.
The guides also help with positioning the wheel between the yokes and aligning the axle. A bolt head secures the axle on one end, and a nut secures it on the other end. Grease is applied to the ball bearings for lubrication and continued smooth running.
The wheel undergoes rigorous quality checks to ensure it can endure multiple rotations before failure occurs.
Factors to Consider When Choosing Caster Wheels
Several essential considerations should be made when selecting caster wheels:
How Much Maneuverability is Required?
For equipment that moves only in a one-dimensional direction, such as large equipment that can be easily moved for cleaning, fixed casters maybe fine.
If you need high maneuverability, swivel casters are recommended. Consider whether swivel locks are needed for equipment essentially moving in a straight line.
There is always mobility with the use of casters but you still must consider the amount of movement freedom you want.
Optimal Caster Mounting Methods
The mounting type, while seemingly inconsequential, can dramatically affect the caster choice. Many applications will use a stem-mounted caster which could restrict weight capacity.
Heavier duty applications, will often use plate mounted casters, which will disperse load across a larger area. Knowing whether the application has specific mounting requirements, will help narrow down caster choice from the numerous options available.
Intended Use of the Casters
The equipment of which the casters will be mounted is an important factor in determining the correct type.
Providing an easy answer determines whether light, medium, or heavy-duty casters are appropriate based on weight. Consideration needs to be given to the working environment, such as advancements for reduced noise, etc.
What are the Different Types of Caster Wheels?
Caster wheels, also known as caster rollers, are important in many applications such as medical equipment, heavy-duty industrial carts, manufacturing, material handling apparatus, furniture, and so much more! Selecting a proper caster wheel is essential to mobility, safety, and flooring protection.
Knowing the various characteristics, styles, and best-use applications of each wheel type will help the user to maximize efficiency and longevity in their environment, whether it is in a warehouse, a cleanroom, the lab, or a food processing facility.
Soft Tread Wheels
Soft treaded caster wheels, made from thermoplastic rubber, mold-on rubber, or polyurethane tread on plastic core, are the best choice for cushy, quiet rides and protection of fragile floor surfaces including hardwood, linoleum and tile.
Soft tread wheels provide great shock absorption and resist a wide range of chemicals, oils and acids. Soft treads roll easier over small debris and create less noise than harder wheels, but they have a softer make-up limiting the load capacity and capacity to roll everything just a little.
Generic applications for soft tread wheels include: medical and pharmaceutical equipment, food service equipment, medical beds, and sensitive loads for light to medium duty workloads.
Their non-marking qualities keep them in preference for environments that want to protect their floor surface appearance.
Ferrous Wheels
Steel wheels—made from either steel or cast iron—are the best option for load capacity, rollability, durability, and protection to impact.
Steel wheels are heavy duty, can take some abuse, are wear resistant and built to carry heavy loads; steel wheels are made to bear the responsibility demanded of industrial carts, warehouse trolleys, factories, and manufacturing plants.
However, for as rugged as steel wheels are, they don’t protect much of a floor, making steel wheels ill suited to any delicate or finished flooring.
When purchasing steel wheels, there are numerous factors to consider in order to maximize ferrous wheels’ performance in arduous applications, such as impact resistance, chemical resistance, and maximum and minimum temperatures.
The wheel is a big part of any caster assembly, and it is essential to select correctly by evaluating criteria such as load rating, operating environment, and surface compatibility. Correct selection allows you to maximize productivity, while minimizing downtime.
Polyurethane Tread Wheels
Polyurethane tread caster wheels are used widely industries for their high load capacities, floor protection, and relative resistance to oil, grease, water, and chemicals.
Solid polyurethane tread can be chemically or mechanically bonded through a variety of cores, plastic, cast iron and aluminum to load ratings of 3,000 pounds.
Polyurethane treaded caster wheels are the most common choice for warehouse shelving, platform trucks, order picking carts, and automated guided vehicles (AGVs).
A potential downside to poly wheels is that tread may separate under a heavy load or through physical damage. This is reduced by molded urethane wheels, in which the urethane wheel is made as all one piece.
Polyurethane wheels are appreciated for their silence, vibration dampening capabilities, and low maintenance costs that processing both manual and automated material handling equipment.
Synthetic Tread Wheels
Synthetic tread caster wheels made from advanced polymers ranging from solid elastomer, which is considered an elastomer, and polypropylene, polyolefin, fiberglass reinforced polypropylene, phenolic resin, and solid nylon, are very popular wheels for their superior impact strength, low rolling resistance, and ultimately their durability for industrial conditions.
Even though these caster wheels can withstand abuse and are durable in high impact and harsh conditions, it is important to note that they are typically not silent wheels and have little to no feel compared to soft materials especially when “rolling over debris into or over uneven floors”.
Phenolic wheels are a good type of synthetic caster wheels. They consist of phenolic resin and macerated canvas and in most cases, are very accommodating to push-pull activity because they roll easily, they have strength, and they have grease and harsh chemical resistance.
Synthetic tread caster wheels are a great option for those requiring non-marking wheels, economical wheels, and wheels that will withstand heat when used on bakery racks, manufacturing plants, or heavy duty carts.
One caveat is to doublecheck environmental use as some synthetic compounds will not work in wet conditions or use on products in constant wet or damp conditions.
Cast Iron and Semi-Steel Caster Wheels
Cast iron caster wheels are made from gray iron and are commonly referred to as semi-steel wheels. Cast iron caster wheels are recommended for applications that require excellent abrasion resistance, long service life, and also for when heavy loads need to roll easily.
Cast iron wheels can be used for high capacity applications in industrial sites such as warehouse, foundries, and steel mills while being exposed to mild chemicals, oily surfaces, and abrasive and abrasive debris, while being sauve to extra-ordinary cold (-45°F) and hot (+250°F) temperature.
Development for industrial cast iron wheels includes several bearing options; roller bearings, precision ball bearings and Delrin bearings, to ensure smooth operation for specific trolley or cart.
Cast iron wheels are great for automated transfer systems and industrial racking because of their strong structure and load ratings. If weight and rough floors are your standard, then cast iron wheels will be your best option.
Flanged Caster Wheels
Flanged caster wheels are designed for guided mobility over steel tracks. Flanged-caster wheel designs eliminate rolling resistance, offer directional control of the load, free up floor space by directing travel routes, and keep loads on the correct route or the designated path.
Flanged wheels are commonly made of cast-iron or steel to provide durability and strength. Flanged wheel designs typically feature a prominent brinell hardness rating usually (130 -150) which allows Fleet to run freely with many types of bearings such as plain bore, straight roller or precision tapered roller bearings, etc.
Flanged wheels are generally used to move equipment in automotive assembly lines, production conveyor systems, and specialized industrial rail systems, etc.
Finally, flanged wheels can take extreme heat – up to 800°F, and they are often used in regard to constant movements at other manufacturer or OEM machine applications when encountering high temperatures, oily environments, or other debris.
Forged Steel or Ductile Steel Caster Wheels
Ductile and forged steel caster wheels are unbreakable load-bearing capacity and immediate shock absorption, and the ultimate in industrial caster wheels.
They are impervious to breakage as a result of normal use. Brick and concrete, forged and ductile created industrial caster wheels are an ideal solution for moving heavy loads in very high temperature, harsh, or adverse conditions of manufacturing and material handling.
Made of forged steel models withstands the fracturing while also bearing the impact. The ductile steel allows for slightly more flex (as well as slight reduction in the weight capacity) without any noticeable decrease in strength.
Builder for extreme industrial situations; including plain, tapered, Teflon and roller bearings; they will preform in extremely arduous manufacturing situations such as metal fabrication workplaces, automotive plants, and steel processing manufacturing facilities where surfaces were oily, metallic, slick, or ridiculous of other adverse issues.
Their resistance to abrasives, oils and mild chemicals, and high temperatures ( +250 °F) allow continuous use on high heat debris unloading operations for heavy-duty equipment, racking systems and heavy carts, etc.
Glass Filled Nylon Caster Wheels
Glass-filled nylon caster wheels provide superior performance in environments with major temperature extremes, high humidity, and exposure to chemicals.
When nylon has a fill of glass, the result is a wheel that is lightweight, tough, non-marking and has excellent resistance to impact, oils, greases and cleaning agents.
Glass-filled nylon wheels can be used for both intermittent and continuous use (up to 490°F, and short durations up to 550°F), in industrial settings as well as offices, retail spaces, garages or warehouses; and can be used on most types of flooring, including on carpet, brick, concrete, linoleum, terrazzo, and wood.
Glass-filled nylon wheels have excellent dimensional stability and can be used in environments with water, steam, mild chemicals, animal fats or extreme heat or cold.
These non-corrosive wheels also have resistance to hard impacts, making them an appropriate choice for food processing, pharmaceutical manufacturing and commercial kitchens.
Hard Rubber Caster Wheels
Hard rubber caster wheels are one-piece molded wheels that are usually grey or black in color. Hard rubber caster wheels typically provide a better load capacity and rolling efficiency than soft rubber wheels.
They have a better ability to resist flattening and cut down on static downtime delivering a dependable solution under unpredictable floor conditions.
Resistance to chemicals, oils, greases, solvents and cleaning agents, make these general-purpose wheels commonly used in utility carts, institutional equipment, and commercial cleaning equipment.
Many different types of bearings have different designs or have different setups but the performance is still reliable across a huge temperature range.
Also, one more thing to consider about a bearing is that the wear itself protects floors and improved acoustic control makes it suited for mobile use across many industries including healthcare, travel, retail, and facility maintenance.
Pneumatic Caster Wheels
Pneumatic caster wheels have air-filled rubber tires for the best shock absorption, vibration dampening, and smooth navigation across uneven surfaces.
Their superb floor protection and ability to roll over debris make them essential for applications transporting delicate, high-value, or sensitive equipment – aerospace, electronics, and hospitals are examples.
Pneumatic wheels are often utilized on outdoor carts, dollies, and warehouse trucks, generally having air cushioning since the ride will absorb impact and stress on the operator, while also protecting the floor they are on from damage, and protecting the product being transported from damage.
Polyolefin Caster Wheels
Polyolefin caster wheels are designed for high performance at an economical price point. Lightweight, non-marking, and non-conductive polyolefin wheels provide excellent abrasion resistance and have good damping and impact performance while resisting oils, water, chemicals, and solvents.
Polyolefin wheels can provide a good and cost-effective option for bakeries, dairy plants, grocery stores, food processing, laundries, and light manufacturing.
The polyolefin wheels can be a great offering on production lines, and get factory managers excited, (i.e. best use case of polyolefin wheels, flexible design of polyolefin wheels.).
Rubber Balloon on Aluminum Caster Wheels
Rubber balloon on aluminum caster wheels have extremely thick and precisely molded gray rubber tread, permanently bonded to a very strong core.
Their cushioned quiet ride on rough or uneven floor surfaces has made these wheels very popular for cargo carts, hospitality trolleys, and audio-visual equipment.
With great durability and non-marking, along with non-conductive and impact absorption capabilities, these wheels really protect floors. It means a lot in high-volume applications, with a lot of people. Quiet and no marks on the floors matter.
V-Groove Caster Wheels
V-groove caster wheels are often gray iron castings that operate in specific material handling environments where controlled motion on angled steel tracks is desired. The machined 90° groove allows for proper load distribution and predictable rolling motion on the track.
V-groove wheels are very popular across the manufacturing, warehousing, and assembly sectors. When properly designed, realized and processed, they are able to move heavier loads over long distances and help eliminate wear on the visitor-inflicted floor.
Braking Systems for Caster Wheels
Integrated brake systems are often used on carts or applications where safety and stability are very important. This is often the case in the industrial caster source.
Brakes stop movement on inclines or undulating surfaces and support an employer’s duty of care obligations.
There are different styles of caster brakes, and they are for specific carts, trolleys and transport applications in logistics, warehousing, healthcare, and assembly line work.
Polyurethane Cam Brakes
Polyurethane cam brakes utilize a cam mechanism for adjustable holding force, which uses a cam to press a plate against the wheel’s running surface.
Cam brakes are a powerful, dependable stopping mechanism that can be actuated by hand or foot, providing ergonomic efficiency and operator safety, and can offer holding power suited for demanding situations on heavy-duty casters, found on industrial carts, medical equipment carts, and manufacturing assemblies.
Polyurethane cam brakes are recognized for durability of materials, ease of use, and low maintenance expectations.
Face Contact Brakes
Face contact brakes are operated by a threaded rod and handle that allow the user to manually engage a plate against the wheel’s surface, ensuring they have a strong reliable hold.
Face contact brakes can lock an extremely heavy load, and be used when carts, vehicles, or equipment must be locked in place throughout maintenance, assembly, or safety precautions.
Although, face contact brakes require more work to operate they have substantial holding force capacity and can also be used in heavy industrial and manufacturing applications.
Side Brakes
Side brakes, or side lock brakes, consist of a simple brake mechanism activated by the pedal to apply a washer against the wheel hub, halting rotation.
Side brakes are low-profile and fit within the swivel radius of the caster, saving space and being easy to apply to compact carts or institutional equipment.
Most appropriate for light-duty applications on the caster wheel, side brakes are easy to use and provide limited holding power while being best suited for applications like hand trucks, display racks, and utility carts in retail and office applications.
Before choosing a braking system for your caster wheels – think about holding strength, how the brake engages (foot or hand), potential operator injuries, and the style of work your employees do every day.
The right choice of brake will help to improve workplace safety and productivity, as well as help employees move equipment properly.
Applications of Caster Wheels
In residential applications, lightweight casters are frequently used in furniture and other household appliances for movement and support.
Casters can be a nice touch on an item like a bookshelf or computer desk. Heavy-duty residential casters are used in commercial and industrial applications to move large, heavy objects.
In aerospace and aviation, heavy-duty caster wheels are necessary for handling large workpieces, machinery, or equipment. Aircraft engine stands, for example, use casters for repositioning and locking. Heavy-duty casters also use a high-speed bearing for aircraft tow bars.
Heavy-duty casters are also used in aviation hangar doors that need to hold a significant weight but still maintain the essential function of easy movement – whether user-controlled or automatic.
Heavy-duty casters are also applied to helicopter landing pads and helicopter trolleys, to transport the helicopter after a landing.
Landing platforms have landing trolleys that use heavy-duty wheels for stability and movement when the helicopter arrives back from flight. The heavy-duty casters are also used in moving shipping containers, which are typically attached at the corner brackets.
In supermarkets, casters are part of the grocery shopping experience, creating easy movement of grocery carts for customers. Unlike an assembly line, hospitals are focused on patient care and comfort.
A hospital setting is still an assembly line, but patient care and hospital environment trump efficiency. The movement in the hospital system is important for patient satisfaction and recovery. For this reason, good, reliable casters are needed in the work of transporting patients and equipment.
While it’s no fun to be in a hospital bed for a long time while you wait for your procedure, patients frequently have to move their personal health monitoring.
Reliable, smooth-rolling casters will make legitimate movement possible. The efficiency of movement is needed as patients move from their bed, to the surgical room, to an area for recovery in the same hospital on a frequent basis.
Benefits of Caster Wheels
Pneumatic wheels are extremely good at absorbing shock which is beneficial when operating on rugged and rough terrain or when the cargo being carried needs to be protected from sudden impact.
Pneumatic wheels can be used in different situations and allows users uses for both off-road and paved surfaces because they are capable of handling uneven ground better than wheels solid wheels.
Noise Reduction – Pneumatic Wheels produce less noise because of their soft rubber tread and it’s shock-absorbing properties allows for reduced noise, which can possibly be harmful to your hearing and provide an easier way of working on the floor.
They help preserve floors and surfaces because of the softer material used in wheel, therefore scratches and other types of wear an tear can be minimized.
Wheels and casters reduce and take the burden of physical effort and strain that employees must experience with heavy loads. They provide easier processes and programs to support the workload with less labor and effort involved.
Pneumatic wheels in a manufacturing and storage place are even becoming more a preferred way of moving parts and stock, making many operations and processes of the manufacturing plant more efficient.
Casters allow ease of use for the user while maximizing supports while minimizing resistance. In supermarkets, caster wheels on shopping carts utilize wheels that allow for low resistance and easy movement. Industrial casters allow users to move and operate large machinery and equipment, while having low resistance to the floor.
Casters definitely have clear advantages in that they give good weight support without breaking down. Caster wheels spin relative to a system of axle system and bearing, therefore cant take as much direct shock as a normal wheel would take. Caster wheels are ideally designed to support loads in a much more effective way.
Casters are produced in various configurations of shapes and sizes and material types depending on what the needs of the application are.
The larger the caster can actually help reduce the strain when moving heavy items and would also allow for a more durable machine or equipment in general when working with heavier items that exceed maximum manual handling weights.
Drawbacks of Caster Wheels
When you’re deciding if a pneumatic wheel works for you, there are things you should think about; the greatest aspect will be the force needed to get it in motion.
Typically, pneumatic wheels require a little more initial push force because the larger contact area and the air in the tire allows for more flex, oscillation.
Also, it tends to be more difficult to maneuver and swivel unless you have a longer swivel lead. Remember to keep an eye on the pressure, too.
Pneumatic wheels are going to require more maintenance because of their risk of flats and punctures and sometimes people will go with semi-pneumatic wheel that has been filled with polyurethane foam.
Semi-pneumatic wheels will not get flats as they do not have air, but you also lose the advantages of using air for cushioning.
Maintenance of Caster Wheels
Maintaining caster wheels involves several important considerations:
Lubricating Caster Wheels
To maximize caster life, lubrication should be scheduled regularly. In general, lubrication will occur every six months with most wheels and fittings.
If a preventative maintenance program is in place that involves inspecting and lubricating all casters and checking the performance of related components and parts, lubrication intervals can be included in preventative maintenance checkpoints, even in an easily accessible maintenance log.
The six months recommendation is not a “one size fits all.” Some casters are used in industrial environments or areas where water or other corrosive agents, are present. In those situations, lubrication should occur more frequently.
If casters have seen water and/or strong chemicals regularly, grease should be applied to the wheels and fittings at least monthly to maintain effective performance and mitigate damage.
Checking Caster Fasteners
The hardware securing the wheels is as important as the grease in the casters. These hardware sets are typically stressed out as they are in continual motion and resistance against the force of gravity.
To ensure you have good operating equipment, I suggest you check the fittings about every month. To check this you need to get your equipment lifted or tilted so you can see the connections at the caster is correct and assess other nuts and bolts and screws and other fittings.
If you see misalignment, wear, or damage, correct the issue right away. Ignoring necessary repairs and replacement of what may appear to be minor items can lead to major problems and sometimes even cause you to replace your entire caster.
Dealing with repairs and replacements is the best way to keep your casters in good condition for the longest period of time.
Caster Wheel Treads
Carrying out appropriate lubrication and securing properly to prevent loose connections in moving systems is essential. However, it is just as important to maintain the integrity of the caster wheel itself.
Casters are generally equipped with treads or rubber coverings for proper rolling motion. However, the operating surfaces of the treads can become flattened or damaged over time.
When a tread wears, it can hasten the wearing of the caster wheel, plus ruin the previously applied lubrications and secure fastenings.
Regular inspections of the treads of the caster wheels and other wear items should be carried out. A damaged tread or wheel should be removed, and replaced, before it creates a problem that could potentially require replacing an entire caster assembly.
Consider incorporating a monthly inspection practice, which will ensure your casters, can provide long-term reliability and efficient use.
Regular Inspection of Caster Wheels
Regular inspections are crucial to make sure casters remain in proper working condition and achieve their full intended lifespan.
Regular inspections, lubrication, maintenance and careful checks on casters can provide many years of good service life, minimizing your replacement or installation costs.
Conclusion
A caster is a wheel or wheel assembly that is meant to be attached to the bottom of a larger object and used to move the object. Caster wheels are the wheels that are attached on the base of device moving equipment and ultimately provide for the mobility of those equipment.
Caster wheels are often needed to move a heavy object using a far lesser amount of force applied to it. Caster wheels do need to be maintained regularly to ensure long life.