Silicon Nitride (Si3N4)

Silicon nitride has excellent mechanical properties for use in Hybrid Bearings such as lower thermal expansion, high rigidity, and wear resistance.

Silicon nitride balls are used in full ceramic and hybrid-ceramic bearings in applications where ultra high-speed rotation is required. The density of silicon nitride is less than half that of steel, reducing the centrifugal force during bearing rotation which enables faster operating speeds.

Silicon nitride balls have an insulating property which is highly effective in preventing electrolytic corrosion. This makes Silicon Nitride balls the optimal solution as a countermeasure against premature bearing failure in electric motors.

The non-magnetic property of silicon nitride is ideal for use in applications subjected to a magnetic field. Using steel balls in these applications may disturb the magnetic field or effect the rotating torque. Silicon nitride balls bearings are ideally used in semiconductor manufacturing equipment and medical diagnostic equipment where magnetic fields are present.

Dimensional Accuracy

We manufacture to an extremely high precision to meet and exceed our customers’ expectations. Super high precision equivalent to G1 is available, which exceeds the ISO Grade 3 specification.

We support the global demand of our customers with a wide diametrical size range of 0.5 mm to 50 mm from our production bases in Japan, the United States, and Thailand.

We can offer cut, drill and flatten based on your drawings. Please CONTACT us.

Grade Diameter
Variation of ball lot
Max. μm
Variation of ball
Max. μm
Deviation from
spherical form
Max. μm
Surface roughness
Max. μmRa
1 ≦2.0 - - - -
3 ≦12.7 0.13 0.08 0.08 0.010
5 ≦25.4 0.25 0.13 0.13 0.014
10 ≦28.575 0.5 0.25 0.25 0.020
16 ≦33.338 0.8 0.4 0.4 0.025
20 ≦48.419 1 0.5 0.5 0.032

In accordance with ISO 3290-2 Rolling bearings – Balls – Part2: Ceramic balls.
We accept orders for non-standard dimensions and specifications upon request.

Diverse Industry Usage

Silicon nitride balls are used in wide range of expanding applications including electric vehicles, wind power generators, semiconductor manufacturing equipment and others.

When an electric current passes through the inside of a rotating bearing on an electric vehicle motor, arcing occurs and the contact surface is damaged. To solve this problem, bearings using silicon nitride balls are used due to the excellent insulative properties.

As the trend for wind turbine farms increase in size and power generation, the tower height, blade length, and generator size have all increased in size and in load requirements.
Silicon nitride ball bearings have the durability and load carrying capacity to bring an efficient solution to meet these demands.
The longevity of silicon nitride balls further lends itself to reduce the risk of unscheduled maintenance, which is costly given the height and location of wind towers.

Silicon nitride ball bearings are used in semi-conductor manufacturing equipment due to the high speeds and low lubrication conditions.
As compared to using steel balls, the use of silicon nitride balls in the bearings has shown to increase bearing life by 50% or more.
By reducing the replacement frequency and maintenance costs, the total life cycle cost of the manufacturing process can be reduced.

By using silicon nitride balls on the wheel hub (bottom bracket) of your bicycle, you can reduce friction, reduce weight and extend bearing life.