Caster Wheel Types and Glossary
This comprehensive guide on caster wheel types delves into the diverse world of caster wheels and their various classifications. Choosing the right caster wheel type is crucial for ensuring optimal mobility and functionality in various applications, from swivel to rigid, pneumatic to polyurethane. Whether searching for the perfect caster wheel for industrial equipment, furniture, or any other application, this guide is your roadmap to understanding the key characteristics and advantages of different caster wheel types.
Caster Wheel Types
- Kingpin- Utilizes a load bearing as well as a thrust bearing to transmit the load. A threaded kingpin and a slotted nut design are the most standard configuration in heavy-duty industrial swivel casters. A kingpin caster allows you to tighten the nut to a larger torque value to decrease the swivel ability.
- Kingpinless– Kingpinless style casters have become highly utilized industrial caster while evolving into a valuable investment for rugged applications that minimize maintenance cost. It is valued for its simplicity and providing a tough caster for industrial applications where shock loading is prevalent. The heat treated inner and outer rings are held in alignment with 1/2 inch high quality hardened ball bearings. The construction of the swivel section puts the ball bearing in a sheer load that provides great strength while providing smooth operation when swiveling in a loaded state. The kingpinless style of caster is a highly desired option when manual ergonomic operation is needed.
- Maintenance Free– Our line of maintenance-free casters are designed to reduce the force exerted to turn, or start rolling when all of the wheels are not parallel. They feature neoprene sealed precision ball bearings and hardened raceways, providing smooth swivel rotation with less effort.
- Spring Loaded– Spring Loaded casters are designed to absorb shocks and minimize the impact to the cart, resulting in smoother movement, reduced risk of damage and less noise. Spring loaded casters are ideal for applications where surfaces are not even or flooring has damage or debris. They are also great for applications where the load may be fragile or highly reactive to vibration, such as small parts or glass. However, to achieve these benefits the spring loaded casters must have the right springs to achieve optimal spring deflection. There is a science to determining proper deflection, the wrong shock absorbing caster can actually do more harm than good. If the spring constant is too high, it could essentially be the same as not having a spring at all. If the spring constant is too low, it could extend the impact of the shock, and continue to vibrate excessively. Rest assured, our engineers are experts in the science of determining the right spring and caster combination for each individual application.
- Rigid Caster – Sometimes referred to as a “Fixed Caster” these casters do not swivel, and are often used in applications as guide wheels.
- Swivel Caster – Caster unit that provides maneuverability by allowing the platform or cart to turn in any direction. These casters have a specific section called a “Swivel Section”, that utilize a variety of types of ball bearings based on load capacity for better maneuverability.
Caster Wheel Bearings
- Annular Ball Bearings – Annular Ball Bearings are machined with hardened raceways. Ideal for applications where maximum rolling ease and quiet operation are needed. Best suited for light to medium-duty loads. Bearing is pre-assembled and the entire unit is mounted in the wheel.
- Delrin Bearings – Delrin bearings are extremely durable under a wide range of temperatures, humid conditions and are corrosion resistant. Wheels with the Delrin bearings are well suited for applications such as steam cleaning or where excessive water or liquid is present.
- Oilite and Bronze Bearings – Oilite bearings are impregnated with oil that self lubricates during use. It is resistant to corrosion and suited for wet applications, slow speeds, high heat and very low maintenance.
- Precision Sealed Ball Bearings– Recommended for maximum rolling ease with no maintenance lubrication required. Quiet operation for medium-duty to heavy-duty loads. Not suggested for severe side or impact loads.
- Precision Tapered Bearings– The precision tapered bearing is the most effective bearing for heavy loads. It is capable of absorbing excessive side thrust loading and can be used where high speed operation is essential. Bearings should be periodically inspected to ensure proper adjustment.
- Roller Bearings– The roller bearing is capable of carrying a greater load than the same size diameter ball bearing. It has a split outer race shell into which the roller assembly is inserted. The bearings are contained by hardened washers.
- Cam Brake– The cam brake is used on lighter-duty casters. This brake provides an efficient, cost-effective hub braking system.
- Dual Side Brakes– The dual side brake is a cost-effective hub brake. Each brake lever must be engaged by the operator.
- Face Contact Brake– The face contact brake is activated by tightening the brake shoe against the wheel.
- Pneumatic Poly Cam Brake– Similar to the standard poly cam brake in operation, the pneumatic poly cam brake offers a greater movement of the brake shoe to compensate for pneumatic tires. The brake is foot-operated.
- Poly Lock– A polyurethane lock roller engages a steel brake shoe against the tread of the wheel providing positive engagement of the tread. Levers can be mounted “toe out” (shown) or reversed to “toe in.”
- Single Side Brake– The single-side brake is an economical brake for medium heavy-duty casters with 6- to 12-inch diameter wheels.
- Wrap Around Brake– The wrap around brake provides total access to the braking system regardless of the caster orientation.
Caster Wheel Types: Swivel Locks
- Demountable swivel lock- The demountable swivel lock is a field-installed option available up to the 71 Series.
- Factory Installed swivel lock- The swivel lock provides notches every ninety degrees for use in straight line movement of the cart. Also available in 1, 3 or 8 position.
- Foot Actuated swivel lock- The locking mechanism on the foot-operated swivel lock is the same as the standard swivel lock. To engage or disengage the lock, there is a pedal that can be operated by foot to improve ergonomics and speed of locking/unlocking a swivel caster.
- Heavy Duty Demountable swivel lock- The heavy-duty demountable swivel lock is a field-installed option available for the 80s and 90s series of casters.
- Heavy Duty swivel lock- The heavy-duty swivel lock provides a longer, more accessible handle made from machined steel.
- Passive swivel lock- The passive swivel lock is used when full mobility of a unit is needed. The swivel lock plunger engages a detent and locks the caster for straight-line movement. When side thrust is applied, the swivel unlocks providing maximum maneuverability of the unit. This swivel lock is NOT RECOMMENDED for towed applications.
- Vertical Mounted swivel lock- The vertical mounted swivel lock is mounted out of the way, under the yoke base of the caster. Used mostly in heavy-duty applications, this swivel lock provides a more secure locking feature.
Caster Wheel Types For Different Applications
- V- Groove – V-groove wheels are constructed of premium G-3000 gray iron castings or hot forged C-1030 steel. The 90 degree grooves are accurately machined into the face of the wheels. A relief groove at the base of the “V” directs the load to each face of the angle track when in use.
- Twergo Lite – The single wheel version of our extraordinary TWERGO® wheels utilizes the same patented face design to reduce initial and continuous push force. TWERGO® Lite makes it easier to push a cart, reducing the amount of energy exerted by the operator.
- Twergo– TWERGO® wheels are designed to achieve unparalleled ergonomic benefits, including reduced initial and continuous push force, and a reduction in force required to turn and maneuver. Furthermore, TWERGO® wheels can help increase productivity by reducing or maintaining existing push force, while increasing the load capacity.
- Swivel on Swivel – Our Swivel on Swivel casters are designed so the 2nd swivel section transfers energy to the 1st swivel section. This aids in rotation and reduces the amount of shifting that occurs. This is extremely beneficial when maneuvering a cart, especially in tight areas. Because these Swivel on Swivel casters reduce the force needed to turn, operator fatigue and injuries are minimized.
- Single Flanged– The flanged wheel is designed to operate on steel tracks to minimize guidance and rolling effort. These wheels are constructed of premium cast iron and steel for high strength and long wear. These wheels are found in various manufacturing settings and are especially beneficial in situations where movement must be limited to prevent injury or to facilitate precision.They boast a maximum capacity of 15,000 pounds per caster, so they can support even the heaviest of loads. Various bore sizes are available for use with keyway or a variety of bearings.
- Dual Flanged– Dual flanged wheels operate on a rail for locating fixtures in a precise position for indexing through a work cycle. Premium cast iron and steel is used for the wheel material to provide high strength and long wear. Various bore sizes are available and wheels can be key-wayed if desired to meet the application.
- Round Tread– The Round Tread wheel, often called a “Donut” wheel, is primarily an ergonomic wheel. Because this wheel is rounded, it reduces the footprint of polyurethane that comes in contact with the floor, resulting in less friction than traditional, flat tread caster wheels. The rounded tread design also helps to push away debris rather than trapping it in the wheel. While the Balloon Wheel is a good product for reducing push-pull force, it does have limitations on weight capacity. It is offered with various tread polyurethane formulations. These include our ErgoTread formulation, which returns energy and helps reduce the force exerted to keep rolling, and a formulation that resists heat build up caused by higher speeds in powered applications such as AGVs or tuggers.
- Polyurethane Wheel– Polyurethane on Cast Iron is the most common type of wheel used in industrial caster applications, offering extreme durability and ruggedness. These types of wheels are capable of carrying heavy loads as great as 11,000 lbs on a single high-density thick tread polyurethane wheel. Polyurethane wheels also feature a higher capacity material than rubber, provide longer wear, and will not damage your floors like cast iron or steel. Caster Concepts processes polyurethane in our facility, and are one of the few caster manufacturers that do so. This ability allows us to maximize quality and flexibility, ensuring you get the best tread formulation for your specific challenge. A wide variety of liquid cast polyurethane wheels are offered.
- Pneumatic wheel– Pneumatic wheels offer the highest cushioning, shock-absorbing caster/wheel, without moving to a more expensive spring-loaded caster. Capacities of pneumatics are limited due to the soft cushioning characteristics of the wheel. The complete line of single or dual-wheel pneumatic casters offers load carrying capacities ranging from 320 lbs. to 7,260 lbs. These industrial pneumatic casters are usually air-filled but can be filled with foam to eliminate deflation issues. Pneumatic casters are ideally suited for moving fragile or delicate cargo where the caster’s overall height is not critical. These casters provide longer wheel life, less maintenance, and high shock absorbency.
- Phenolic Resin– A wide selection of phenolic resin wheels are available in inventory. The wheels shown in the chart are laminated phenolic. The continuous wrap process of a phenolic wheel makes it a longer wearing product that has a higher resistance to chipping and fraying. Standard black phenolic wheels (30) feature macerated canvas duck compression molded with premium phenolic resins to produce a value/price relationship. High temperature phenolic wheels (32) provide continuous service up to 425˚ Fahrenheit and intermittently to 500˚ Fahrenheit. Laminated phenolic wheels (35) feature a continuous wound tread with a macerated canvas center. The wheels have a 40% higher impact resistance and carry up to 25% higher load than standard phenolic wheels.
- NyTec-MD– NyTec-MD is a nylon filled material which provides a high load capacity, floor protective wheel. Wheel capacities approach those of similar cast iron and steel wheels. NyTec-MD material is resistant to most harsh environments. The non-abrasive and vibration dampening material actually provides a quieter operation when compared to steel or cast iron wheels. When used in wet environments, plain bore NyTec-MD wheels can be used as the material is self lubricating. NyTec-MD wheels are offered with precision tapered, precision ball, and straight roller bearings. For special applications, contact the factory.
- Forged steel– Forged steel wheels are hot forged from high carbon steel billets heated to 2,400 degrees Fahrenheit and then repeatedly hit by high tonnage forging hammers. This process enhances the grain structure and increases the ductility and tensile strength (64,000 psi) of the wheel. The wheels are then precision machined flat with rounded edges to finished tolerances. Forged steel wheels offer the greatest load capacity, impact strength, and rollability of all caster wheels.
- Mold on Rubber– Caster Concepts offers the highest quality domestic Mold On Rubber wheels. Our mold on rubber wheels consist of a soft black, 70 durometer rubber tread permanently bonded on Class 30 gray iron centers. Mold on rubber wheels provide excellent floor protection, a cushioned and quiet ride for the product being transported, and they absorb shock and vibration. When used as a drive wheel, mold on rubber caster wheels provide excellent grip. They are a cost-effective means of reducing noise while maintaining reasonable carrying capacities.
- Ductile Iron– Ductile iron wheels feature many of the same characteristics of cast iron; however, the ductile iron wheel has higher tensile and yield strengths. Ductile iron can also reach tensile strengths similar to forged steel. Its greater strength and flexibility — and less brittle-like cast iron tendency — help ductile iron become a better alternative in shocking applications.
- Drive/ Keyway– Keyway drive wheels are used in various power transmission applications and involve securing a wheel to a shaft. The keyways are cut to fit a keywayed shaft and are held in place with two set screws. One set screw is placed over the key and one at 90 degrees to the keyway. The most popular models are made of rubber or soft polyurethane. However, Keyway wheels are also manufactured in other materials, such as forged steel or cast iron, and are available in numerous wheel widths and sizes. Quotes for specific requirements are also readily available.
- Cast Iron– These cast iron wheels are constructed of premium Class 30 gray iron for maximum load capacity and impact strength. The wheels feature heavy cross section castings for heavy duty use, abrasion resistance and a long service life. Each wheel is precision machined with rounded edges to finished tolerances. Built for high capacity applications, the cast iron wheels can withstand extreme heat. Precision tapered bearings are available to complement the characteristics of the wheel.
- Angle Reinforced legs– Heavy-duty angle reinforced legs provide maximum strength and rigidity. Reinforced Legs are constructed of either angle iron on the outside of the leg or gussets on the inside designed to strengthen the caster when exposed to side loading. A good example is our Hercules Casters.
- Caters with Steering Tubes– Slots for steering handles allow precision motion control for casters with steering tubes. Steering tubes are used on industrial casters that carry heavy loads and need to be manipulated in very tight places.
- Heat Treated Raceways– Heat-treated raceways in swivel casters are designed to prevent brinelling of the raceways.
- Sealed Wheels– Rubber inserts provide maximum protection against debris within sealed wheels.
- Threaded Zerks– Threaded Zerks Grease fittings for every size caster.
- Toe Guard– The toe guard is mounted approximately one-half of an inch off the floor to help protect workers’ feet. It can be used in both manual and power applications.
- Track Brush Wiper– Add a track wiper brush for extra protection against debris and build-up. Track wiper brushes are utilized when any type of wheel is running on a track where debris can stop the movement, damage the wheel or take it off the track.
- Medium Duty- As our lightest offering, Medium Duty Casters handle loads weighing less than 900 lbs. Whether you need an ergo tread, a standard or high-performance poly, pneumatic, or mold on rubber, you’ll find a caster for your material handling application. Popular Medium Duty Brands from Caster Concepts Include: CasterShoX, ErgoXcel, and Twergo.
- Medium Heavy Duty- Our Medium Heavy Duty Casters capacities range between 900 lbs. to 1,999 pounds and are a very commonly used caster for hand carts and dollies in the automotive and aerospace industries. Medium Duty Casters feature several ergonomic caster brands including: Twergo, Twergo Lite, Twergo Xtreme, Swivel on Swivel, and CasterShoX. In addition, our Hercules Casters utilize reinforced legs to withstand heavy side load impact.
- Heavy Duty- Heavy Duty Casters fall between 2,000 and 4,999 lbs. Above this weight range include Extra Heavy Duty and Super Heavy Duty. Below this range is Medium Duty and Medium Heavy Duty. You’ll find these casters in many industries including aerospace, automotive, heavy equipment, military and many others.
- Extra Heavy Duty- Our Extra Heavy Duty Line of Casters can handle loads from 5,000 lbs. to 16,999 lbs. Along with our Super Heavy Duty Casters, these brutes are designed to handle a variety of material handling challenges like difficulty swiveling, protecting a payload, overall height constraints, extreme heat, rough floor conditions, or high maintenance costs.
Super Heavy Duty- For high-capacity casters designed to handle loads of 17,000 pounds up to 50,000 lbs. (we’ve even built casters that can carry 100,000 lbs.) An excellent example of our Super Heavy Duty Casters is our 99 Series industrial caster – which can range from 10 to 22 inches in diameter and is available in single- or dual-wheel configurations. The 99 series features a dual load race design, which assures smooth rotation of the caster, and superior load capacity on any surface and under the most extreme weight conditions.