YDTech™ Grade 0 Silicon Nitride Ceramic Rollers for Extreme Applications

As a leading manufacturer of Grade 0 high-precision silicon nitride ceramic rollers, we specialize in delivering uncompromising quality for the most demanding engineering challenges. Our products range from miniature sizes (down to 2×2 mm) to medium dimensions (45×45 mm), all manufactured to the strictest Grade 0 (G0) tolerance class – the highest precision level for cylindrical rollers.

Our miniature D2×L2 mm rollers are widely used in dental turbine bearings operating at speeds up to 600,000 rpm. The low mass and ultra-smooth surface enable vibration-free, quiet operation essential for patient comfort and surgical precision.

In chip bonders, wafer handling robots, and hard disk drive spindles, our rollers provide the low particle generation and non-magnetic properties required for ISO Class 5–6 cleanrooms. The electrical insulation also prevents current-induced bearing failures in sensitive electronic manufacturing equipment.

density(g/cm3)	relative density(％)	elastic modulus(GPa)	compression strength ratio(25C)	Hardness HV(GPa)
3.260.02	>99.5	300-320	40-50	16-20
Fracture toughness(MPa.m1/21/2)	Bending trength(MPa)	Poisson's ratio	Linear expansion coefficient10-6K-1	Webuller modulus
6.0-9.0	600-1000	0.25	3.1-3.3	12-15
Thermal conductivity (W.(m.K)-1)	Specific resistance ratio	Corrosion resistance	Size stability	Magnetic
15-20	1018	Excellent	Excellent	None

Our rollers are specified in aerospace gyroscopes, satellite mechanisms, and missile guidance systems, where reliability under extreme temperatures, vacuum, and radiation is non-negotiable. The combination of high stiffness and low thermal expansion ensures dimensional stability over a wide operating range.

For CNC spindles and high-speed machining centers, our Grade 0 rollers provide the rigidity and rotational accuracy required for micron-level machining, reducing downtime and improving surface finish quality.

In electric vehicle (EV) traction motors and wind turbine generators, our ceramic rollers solve the critical issue of electrical erosion caused by high-frequency inverter currents, extending bearing life by 3–5 times compared to steel alternative Self-Lubricating & Low Outgassing – Ideal for vacuum and clean-room environments

diameter and roundness of cylindrical rollers

I_G=roller diameter gauge interval.

precision cylindrical rollers of loose roller bearings

grade	Dw/mm		VDwL	IG	regulation values			▽Cir
	exceed	to	max					max
G0	-	18	1	1	-10,...,-1	0	+1,...,+5	0.3
G0	18	30	1	1	-10,...,-1	0	+1,...,+5	0.4
G1	-	18	2	1	-10,...,-1	0	+1,...,+5	0.30.4
G1	18	30	2	1.5	-10.5,...,-1.5	0	+1.5,...,+6	0.5
G2	-	18	3	1	-10,...,-1	0	+1,...,+5	0.5
G2	18	30	3	1.5	-19.5,...,-1.5	0	+1.5,...,+6	1.0
G2	30	-	3	2	-20,...,-2	0	+2,...,+6	1.5
G3	-	18	1	1	-10,...,-1	0	+1,...,+5	1.0
G3	18	30	1	2	-20,...,-2	0	+2,...,+6	1.5
G3	30	-	5	3	-24,...,-3	0	+3,...,+6	2.5

We combine advanced ultrasonic-assisted grinding, laser measurement systems, and 100% dimensional inspection to ensure every roller meets Grade 0 specifications. Our production capacity covers: Diameter: 2 mm – 45 mm Length: 2 mm – 45 mm Tolerance class: G0, G1, G2 available upon request Material: High-purity Si₃N₄ (≥ 99.5%)

Each batch undergoes rigorous quality control, including roundness, surface roughness, dimensional accuracy, and material integrity testing, ensuring full traceability for critical applications.