What is the difference between a Wheel and a Caster?
The perfect guide for understanding Casters and Wheels
What is a Caster?Casters are the complete assembly of the wheel attached to a frame known as a Caster Yoke, Caster Rig, or Caster Fork. Caster frames go by different names, but they are technically the same apparatus that holds the caster wheel to make up a complete caster assembly. For this informative Caster guide, we will call caster frames by the more common name: Caster Forks. Caster forks come in either Swivel or Rigid versions, depending on the required application. Most Swivel Caster Forks are made up of 1045 ASTM steel and either cold or hot forged to increase the strength and durability of the steel. Although Caster forks also come in a variety of materials, including Stainless Steel Casters and Chrome Plated. Swivel caster forks usually come with a double ball bearing raceway, which is known as an upper raceway and a lower raceway. Caster fork raceways allow the swivel casters to turn 360 degrees with ease. Depending on the quality of materials used in the manufacturing process, some swivel casters will turn much easier and some more difficult. This all depends on the materials used to manufacture the caster, the ball-bearing materials, and the inner raceways that contain and hold the ball bearings. Some ball bearings are hardened and heat-treated, while some are not. After the caster forks are manufactured, they are then assembled with a caster wheel and a nut and bolt to hold the wheel to the caster fork. Once all parts are assembled you now have what is known as a Caster. Casters come in different sizes and weight capacities for thousands of applications. Heavy Duty Casters generally come with a much larger wheel diameter and tread width along with a wheel that can withstand a heavier load capacity. Heavy-duty Casters are commonly seen with either steel wheels or polyurethane on cast iron wheels, allowing a much greater weight capacity than many other types of wheels in the industry. Lighter duty casters and institutional casters require less weight capacity, allowing a greater variety of wheel combinations and materials to suit your application needs perfectly. Casters also come in Stainless Steel for wet and corrosive environments to prevent rust while offering the caster a much longer service life when exposed to water or harsh chemicals.
What is a Caster Wheel?Caster Wheels are simply one component of a caster. Wheels for casters can come in an array of wheel materials, including; Polyurethane
, High Temperature
, Thermo Plastic Rubber
, Mold on Rubber
, Ductile Iron
, and countless other wheel materials, to name a few. Caster Wheels generally have one or two pieces to the wheel. Some are solid one-piece wheels such as a Phenolic, Nylon, Polyolefin, or Solid Polyurethane Wheel. One-piece caster wheels are more resistant to tread delamination, wear much better, and can typically handle more abusive shock load applications. Two-piece caster wheels are known as Polyurethane on Polyolefin or Polyurethane on Steel, to name a couple. Two-piece caster wheels are either Mechanically bonded to the core or Chemically bonded with industrial glues to allow the tread to bond to the wheel's core. The benefits of two-piece wheels sometimes offer higher weight capacities with superior floor protection allowing a Polyurethane tread to be bonded to a steel core. This type of wheel offers high load capacities and also non-marking floor protection at the same time. In lighter-duty caster wheels, you might notice two-piece casters such as polyurethane on a polyolefin core wheel. These types of wheels are made for performance and meet specific price criteria and an array of thread color options. Lighter duty two-piece caster wheels are generally mechanically bonded to a polyolefin core which helps prevent the wheel from delaminating from the tread during extensive use. Rolling wheels causes friction and heat build-up, so a mechanical bond is the best way to prevent the tread from falling off the wheel's core. Caster wheels come with different bearing options including, Roller Bearings, Precision Bearings, and Delrin Bearings. Each bearing offers different performance characteristics depending on the application. Roller bearings, also known as needle nose bearings, can handle greater weight loads than a precision bearing. Precision bearings handle side thrust much better than a roller bearing. Delrin bearings are typically used in cleanroom or medical applications that cannot have metal around specific machines or corrosive chemicals. Need to know more about a specific caster wheel material? Click Here to visit our Wheel Material Guide.
Casters and Wheels work together in tandem. Without a Caster Wheel, you would not have a Caster. When the right materials are used in conjunction with a caster and wheel application, you can reduce push-pull force, increase ergonomics, and save money by reducing the time frame of replacements. Many factors go into deciding the best wheel and caster fork for each application. For expert advice and help, don't hesitate to contact our CasterHQ Experts below, and we will help you decide which caster is best for you.