How to Select the Proper Caster and Wheel ?

Many things need to be considered when choosing the right caster for your task, and these considerations depend on where you’ll be using the caster. The application that your caster will undergo determines the caster qualities that you’ll need. So we need to consider what the most important criteria are as following:

Swivel Radius:

The swivel radius is the measured horizontal distance from the vertical center line of the kingpin to the outside edge of the wheel tread. The swivel radius specifies the minimum clearance required for a mounted caster to swivel 360 degrees. The larger the swivel radius, the easier the caster will rotate.

Wheel Diameter:

Make sure you consider what type of floor protection is required. Your wheel must be large enough to negotiate your unique floor conditions, such as cracks in the floor, tracks, moldings, or any other unforeseen obstacles.

Dynamic Load & Load Capacity: 

Each caster is designed and built to support a certain maximum load while in use, and exceeding this maximum can cause damage and deterioration of the caster, which can potentially lead to catastrophic failure. For this reason it is important to know the maximum load you will have so that you can divide this evenly among the casters you will use.

Floor Conditions

In general, it is best to use hard wheel materials on soft floor surfaces and soft wheel materials on hard floor surfaces to prevent damage to the wheels and marking of the floors. Make sure the wheel you select is large enough to pass over cracks in the floor, tracks, moldings and other obstructions. Choosing the right type of wheel material the first time can save you a lot of problems and anguish later, especially when it’s time to change your casters.

Material of Wheel:

  • Rubber (R): with the features of good elasticity, mobility and weather resistance; bad oil and corrosion resistance.The weakness of rubber wheel is that it is easy to cause black dirt on the ground.
  • Polypropylene (P): hard texture, good water resistance and drug tolerance; economic.   
  • Polyurethane (U): high-strength, abrasion resistance, excellent bearing capability, no friction marks left on the ground, but it will be hydrolysis over time. 
  • Thermoplastic Rubber (TPR): With high elasticity, it will easily absorb the vibration with low noise while moving, but easily deform, not good for heavy loading.
  • Nylon (N): high hardness, good toughness, oil and water resistance, good weather resistance, usually for industrial environment and food equipment and machinery.
  • Cast Iron (C): corrosion, oil and abrasion resistance, good weather proofing with high resisting force, high loading, not easy to deform, but easy to generate louder noise while moving.

Unusual Conditions

Each wheel has certain characteristics, which will give the best results where unusual conditions exist. Check conditions and then select a caster and/or wheel. Be sure to consider unusual environmental conditions such as moisture, extreme heat or cold, exposures to chemicals, blood, fats, oils, salt, etc.

Other considerationsHow to mounting your casters? Options include top plates, which are bolted into place and screw threads, or press threads that are inserted into a hole in your cart or trolley are also available.