The high-carbon, stainless steel ball is made from one of the hardest stainless steels and complies with ASTM A276, ASTM A756 and AMS 5630 as well as MIL-SPEC MS19063B. The sphericity is within 0.6 nm. The ball is required for flat air bearings: Air bearing round | Air bearing square
| Ball diameter | Compatible with | Holding plate for ball |
|---|---|---|
| 13 mm | OAVF20L40 | OAVBR13R18 |
| 13 mm | OAVF25L50 | OAVBR13R18 |
| 13 mm | OAVF40L50 | OAVBR13R21 |
| 13 mm | OAVF40L80 | OAVBR13R21 |
| 13 mm | OAVF50L100 | OAVBR13R21 |
| 25 mm | OAVF100L200 | OAVBR25R40 |
| Ball diameter | Compatible with | Holding plate for ball |
|---|---|---|
| 13 mm | OAVR025R | - |
| 13 mm | OAVR040R | OAVBR13R21 |
| 13 mm | OAVR050R | OAVBR13R21 |
| 13 mm | OAVR065R | OAVBR13R21 |
| 20 mm | OAVR080R | OAVBR20R32 |
| 20 mm | OAVR100R | OAVBR20R32 |
| 20 mm | OAVR125R | OAVBR20R32 |
| 25 mm | OAVR150R | OAVBR25R40 |
| 25 mm | OAVR200R | OAVBR25R40 |