Backrind is a torn or gouged condition (recess) at the mold parting line caused by thermal expansion over sharp mold edges or by premature cure.
| Specification | Max Allowable Backrind Width (inches)** |
Max Allowable Backrind Depth (inches)** |
|---|---|---|
| AS708* | Not Specified (.005 is standard reject for any defect) | Not Specified |
| ISO 3601-3 CS | 0 | |
| AS871 | 0 | |
| ISO 3601-3 S, DIN 3771 S | .0039 | .0020 |
| ISO 3601-3 N, DIN 3771 N | .0071 | .0031 |
| MIL-STD-413C | 0 | |
| RMA OR-1 A | 0 | |
| RMA OR-1 B | .005 | .003 |
**Data above shows maximum allowable Width/Depth of Backrind assuming an O-ring cross sectional diameter between 0 and .1 inches.
