What is a slewing ring bearing?

A simple question. Do you know the answer? The slewing ring is known by many names, slew ring, turntable bearings, lazy Susan bearings to name a few, but at igus® we refer to them as a PRT slewing ring bearing.

So, what is a slewing ring bearing?

In the simplest form, the slewing ring bearing is a bearing which rotates whilst accommodating both axial and radial loads. This rotational bearing can be found in applications that require turning function in either horizontal or vertical movement. They are often compared to ball bearing rings, however, these slewing rings tend to be much wider and often have fixing holes, so they can be fixed to a machine or structure.

How does the igus® PRT slewing ring differ to conventional ones?

slewing ring bearing

As with a large range of igus® products, the PRT slewing ring consists of polymer elements manufactured from iglidur® tribological materials. These polymer parts replace the requirement for metal rollers or balls, allowing the slewing ring to rotate smoothly and quietly.

The outer rings of the slewing rings are normally manufactured in lightweight anodised aluminium but there are now stainless-steel versions as standard too. The stainless-steel versions are ideal for applications involving high temperatures or excessive contact with certain chemicals.

When comparing the traditional slewing rings with the igus® PRT’s, there are further advantages of using the igus® versions:

  • Weight
  • Cost
  • Lubrication & maintenance-free

Why is a reduction in weight important?

Some applications require machines to be as lightweight as possible. Making weight reductions can be easy when you replace complete metal assemblies with a combination of metal and polymer. With the igus® PRT slewing ring, weight reduction is simple, and it doesn’t compromise the load capacity. The slewing rings are tried and tested in the igus® laboratory and have demonstrated their long service life in the multiple tests run.

Where can you use a slewing ring bearing?

Slewing rings are versatile and adaptable bearings suited for a multitude of applications. Any applications where rotation is required, a slewing ring bearing is ideal.

Applications such as:

  • Wind turbines
  • Rail vehicles
  • Water treatment plants
  •  Distilleries
  • CNC Machinery
  • Aerospace & Automotive interiors

These are just a few of the types of applications where we find slewing ring bearings used, but the possibilities are endless.

Can igus® slewing rings compare to traditional ones?


People have a misconception that if plastic parts are used that this weakens the structure, therefore, reducing its capacity.

This isn’t true.

The igus® PRT slewing rings are designed and constructed to optimise the slewing ring movement. Using the iglidur® materials for sliding elements, ensures that the movement remains smooth, and combining it with anodised aluminium allows these bearings to be:

  • 100% maintenance-free and self-lubricating
  • Corrosion-resistant and hygienic
  • Wear-resistant
  • Resistant to dirt, dust and humidity
  • Robust
  • Cost-effective
  •  Ready to install & easy to assemble
  • FDA options available
PRT bearing

Another key element of the igus® slewing ring bearings, in comparison to other manufacturers, are our extensive material ranges, not only for the outer rings but the sliding elements too. We can custom design and manufacture specialised slewing rings, anodise the outer rings in non-reflective colours, we have additional parts available as standard to fix location points on the slewing ring to restrict the rotation, and mechanical stops to locate home positions.

They really are ideal for so many applications.

If you want to find out more about the latest PRT slewing ring to join the range, you can read all about it here

For more information on the range of slewing ring bearings please visit the website or contact the Product Manager Dean Aylott.


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