Design Factors for Simplicity® Bearings

When designing applications to use Simplicity® linear bearings, there are factors to consider within your application, such as size, temperature, orientation, and running clearances.

Measurement Category

We often hear these questions when discussing our Simplicity® family of linear plain bearings: “Why are there different colors? Why are there red, blue, and green bearings?” The answer is quite simple. The colors relate to three different measurement standards common in the industry. These three categories are:

Inch Series (Red)

  • Designed to interchange with industry standard inch series linear bearings.
  • Sizes for shafting ranging from 3/16” up to 4”.

ISO Metric Series (Blue)

  • Designed to interchange with European ISO metric standard linear bearings.
  • Sizes for shafting ranging from 5 mm to 80 mm.

JIS Metric Series (Green)

  • Designed to interchange with Asian JIS metric standard linear bearings.
  • Sizes for shafting ranging from 6 mm to 150 mm.

All of the Simplicity® linear bearings come standard with the FrelonGOLD® self-lubricating liner and do NOT require external lubrication.

Precision vs Compensated

Within the family of Simplicity® linear bearings, precision and compensated are terms that refer to the two classes of available running clearances. It is important to understand the difference in these two classes for the design and installation process to ensure that bearing systems will perform properly.

If you are building a linear slide system or replacing existing bearings, a simple way to check for the difference between a precision and a compensated bearing is to place each on a shaft. In this side-by-side comparison, you will distinctly feel more play caused by the greater clearance in the compensated bearing. Note that many parallel shaft applications will run with an “FL” (Precision) bearing on one rail and “FLC” (Compensated) bearing on the opposite rail to accommodate for slight misalignments. Below is a quick reference comparison for Simplicity® bearings:


  • Use the prefix “FL” in the part number.
  • Has the tightest running clearance (approximately .001” or .025mm total).
  • Recommended for applications that require tighter tolerances and stiffened assemblies.
  • Not recommended for parallel shaft applications where misalignment can lead to binding issues.


  • Use the prefix “FLC” in the part number.
  • All dimensions the same as precision bearings, except for more clearance in the I.D. between the shaft and bearing (approximately .003” or .07 mm total).
  • Ideally suited for parallel shaft applications.