GRADE SHEET
| GRADE | ALLOWABLE BALL DIAMETER VARIATION | ALLOWABLE DEVIATION FROM SPHERICAL FORM | MAXIMUM SURFACE ROUGHNESS*AA | BASIC DIAMETER TOLERANCE (+/-) |
| 25 | .000025 | .000025 | 2.0 | .0001 |
| 50 | .000050 | .000050 | 3.0 | .0002 |
| 100 | .000100 | .000100 | 5.0 | .0005 |
| 200 | .000200 | .000200 | 8.0 | .0010 |
| 500 | .000500 | .000500 | N/A | .0020 |
| 1000 | .001000 | .001000 | N/A | .0050 |
VALVE GRADE SURFACE FINISH
| SIZE RANGE | MAXIMUM SURFACE ROUGHNESS*AA |
| 5/8" TO 1" | 1.5 |
| 1 1/16" TO 1 3/8" | 2.0 |
| 1 7/16" TO 5" | 3.0 |
* ARITHMETICAL AVERAGE