When choosing a swivel section, it’s best to understand the application first and what you are trying to accomplish. We typically calculate a total load over three casters in a four-caster setup to allow for an ample safety factor when moving on uneven floors.
Knowing a sufficient rating for each caster you need is the best starting point before choosing your swivel section. The three most common swivel sections are kingpin style, kingpinless, and maintenance free. I will explain each of those options and the best applications to consider using each option.
Kingpin swivel sections consist of a bolt that runs through the center of the swivel section. Its purpose is to sandwich the load bearings and thrust bearings between a swivel section’s top plate and yoke base. Now that other options have come to market, the kingpin is more of a traditional caster. You will use this style if you plan to maintain the caster.
Because of this design, you can take the caster apart and perform maintenance to the bearings, which can extend the overall life of the caster. It also allows for adjustability, as the swivel section wears over time. In addition, you’ll continue to get life out of the caster by tightening the kingpin. The most common use is for extremely heavy loads where kingpinless or maintenance-free casters cannot handle the high capacity.
The Kingpinless swivel section is the most commonly used. It consists of a yoke base and a top plate that mate with a ball race. Loading carbon steel balls into a load hole fills the ball race so the top plate and yoke don’t come apart. This creates a bearing similar to a ball bearing. The result is a free-spinning swivel section that allows for an easy change of direction.
The kingpinless design does not have a kingpin as a constraint and distributes the load over a larger area. They are designed with a grease fitting for routine maintenance to extend the caster’s life. Kingpinless are great for heavy loads and with the correct grease, even perform well in high-temperature applications.
Maintenance-free swivel sections have a precision sealed ball bearing pressed into a yoke base and the top plate to hold the two pieces together. This design allows for the most consistent and smooth spinning swivel section. The sealed ball bearings prevent dirt from getting in and grease from getting out, resulting in a long caster life while saving time and money from maintenance. Maintenance-free swivel sections are best for ergonomic improvements as they have the smoothest spinning swivel section. They are also best if you don’t plan on maintaining the casters on a routine basis.