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ASTM F2094 Si3N4 CERBEC BALL SPECIFICATIONS
| Grade |
Allowable Ball Diameter Variation |
Allowable Deviation from Spherical Form |
Maximum Surface Roughness Ra |
Allowable Lot Diameter Variation |
Basic Diameter Tolerance |
| 2C |
0.05 (2) |
0.05 (2) |
0.004 (0.15) |
0.08 (3) |
+/-0.51 (+/-20) |
| 3C |
0.08 (3) |
0.08 (3) |
0.004 (0.15) |
0.13 (5) |
+/-0.51 (+/-20) |
| 5C |
0.13 (5) |
0.13 (5) |
0.005 (0.20) |
0.25 (10) |
+/-0.76 (+/-30) |
| 10C |
0.25 (10) |
0.25 (10) |
0.006 (0.25) |
0.51 (20) |
+/-2.54 (+/-100) |
| 16C |
0.40 (16) |
0.40 (16) |
0.009 (0.35) |
0.80 (32) |
+/-2.54 (+/-100) |
| 24C |
0.61 (24) |
0.61 (24) |
0.013 (0.50) |
1.22 (48) |
+/-2.54 (+/-100) |
| 48C |
1.22 (48) |
1.22 (48) |
0.013 (0.50) |
2.44 (96) |
N/A |
| 5 Steel for Comparison |
0.13 (5) |
0.13 (5) |
0.02 (0.8) |
0.25 (10) |
+/-1.0 (+/-40) |
[ Micron (Micro-Inch) ]
Surface Finish
CERBEC balls are known worldwide for their extremely smooth surface
finish. Our manufacturing process is totally dedicated to Si3N4 finishing.
This focus yields surface finish typically < 0.10 micro inch (< 0.003 micron)
consistently from batch to batch for the tens of millions of balls we
produce annually. Reduced bearing friction from Si3N4 is a function of
smooth surface finish - it must be done right all at the time. CERBEC balls
have over 10 years' history of superior surface finish.
Surface Quality
CERBEC balls are also known for superior surface quality. CERBEC balls are free of
cuts, scratches, scuffs, and other breaks in surface continuity. While many companies pay attention to surface finish, CERBEC balls are the only ones on the market made with great focus on surface quality. This attention to detail translates into longer life and more reliable operation of your bearing.
Geometry
CERBEC ball geometry far exceeds ASTM F2094 for silicon nitride balls. Beyond superior surface finish and quality, CERBEC balls are extremely round with tightly controlled diameter variation in every lot. CERBEC balls can also be made with tightly controlled harmonics or waviness. The highest precision bearing companies worldwide specify CERBEC balls to minimize noise and vibration at the highest of speeds.
Optimized Si3N4
CERBEC balls are made from Si3N4, specifically engineered for bearings.
Our Si3N4 materials are all Hot Isostatically Pressed (HIP) for a pore-free microstructure with micron-sized grains. For decades, Saint-Gobain has pioneered HIP technology to yield the highest quality, superior performance Si3N4 for bearings.
Availability
CERBEC balls are made in Grade 5, 3, and better. They are stocked worldwide in a wide range of sizes (1/32" to 1-1/8") and increments. We recognize that bearing companies need a selection of ball increments to build bearing quickly and affordably. That's why we are the only Si3N4 ball maker that stocks from 3 to 9 increments to each ball size (M4 to P4 in some cases). For our best clients, we maintain stock in their plants to assure balls are always ready for bearing assembly.
All Ceramics Are Not Create Equal
CERBEC ® balls' unique, patented formulation, microstructure, and precision finish imbue it with superior performance characteristics. Almost all ceramic rolling elements present some advantages over steel. The precision-crafted quality of CERBEC balls far outperforms not only the best steel, but also all other ceramics, in nearly every instance.
Saint-Gobain Advanced Ceramics Bearing Materials - Typical
Properties
| Density [g/cm3]
(% Theoretical)
|
3.16 [>99.9%] |
3.21 [>99.9%] |
| RT Flexural Strength [MPa] |
>900 |
>1000 |
| Weibull Modulus |
>15 |
>25 |
| Elastic Modulus [GPa] |
320 |
310 |
| Poisson’s Ratio |
0.26 |
0.27 |
| Vicker’s Hardness HV10 |
1550 |
1600 |
| Fracture Toughness
[MPa * m1/2]
|
>5.5 |
>6.5 |
| Thermal Expansion Coeff.
10-6/°C; [RT-1000?C]
|
2.9 |
3.7 |
| Thermal Conductivity
[W/mK] @ 25°C
|
29 |
34 |
| Electrical Resistivity
[Ω-cm]
|
1014 |
1014 |
| Dielectric Constant @ 1MHz |
8.0 |
8.0 |
| Corrosion
5% HF Solution, 500 Hours Weight Loss/ Surface Area [g/cm2]
|
0.68 |
0.10 |
| Corrosion
5% HCL Solution, 500 Hours Weight Loss/ Surface Area [g/cm2]
|
0.0002 |
0.0036 |
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