Let’s start by explaining friction in simple terms.
Imagine placing an object on a flat floor and trying to pull or push it straight from the side. It always takes some amount of force to move it. This is because, even if the surface looks flat, both the bottom of the object and the floor have tiny irregularities that catch against each other, resisting the movement.
This resisting phenomenon is called friction.
The force required to move the object changes depending on the roughness of the contact surfaces and the weight of the object. This force is called frictional force, and the larger the required force, the greater the frictional force.
For example, moving an object placed on rough concrete requires more force than moving one on a smooth wooden floor. Similarly, the heavier the object, the stronger it is pressed against the floor, and the greater the frictional force. We experience this in everyday life—heavier objects simply require more effort to move.
While we used the example of an object on a floor, friction occurs wherever surfaces rub against each other. To quantify this, we use the friction coefficient. Simply put, the friction coefficient is a measurable value that expresses how easily two surfaces slide against each other—whether they glide smoothly or resist movement.
This concludes our basic explanation of friction.
At Kashima Bearings, we mainly handle plastic bearings. Many of you may know that plastics come in a variety of types.
Just like wood, rubber, or metal, plastics also generate friction, and each type of plastic has a different friction coefficient. When it comes to bearings, “low friction” = “low friction coefficient” = “smooth rotation.” By using bearings with low friction, you can reduce energy consumption and minimize wear on parts, which in turn helps reduce costs.
However, a low friction coefficient alone does not necessarily make a material suitable. For example, when selecting bearings, we must also consider factors such as load, rotation speed, temperature, and chemical resistance, in addition to friction.
Of course, cost is also an important factor to consider.
