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
Note: No tool marks or defects discernible to the naked eye are permitted.
**Data above shows maximum allowable Width/Depth of Backrind assuming an O-ring cross sectional diameter between 0 and .1 inches.

Backrind diagram