This SAE standard identifies and defines the most commonly used terms for piston ring-goove charactersitics, specifies dimensioning for groove widths, and demonstrates the methodology for calculation of piston groove root diameter. The requirements of this document apply to pistons and rings of reciprocating internal combustione ngines and compressors working under analogous conditions, up to and including 200 mm diameter and 4.5 mm width for compression rings and 8.0 mm width for oil rings. The specifications in this document assume that components are measured at an ambient temperature of 20 degrees C (68 degrees F). Tolerances specified in this document represent a six sigma quality level.
Rationale: SAE J2275 was reviewed by the SAE Piston and Rings Standards Committee. Numerous clarifications were made to the standard to help the reader better understand the content of the standard. New figures were added to improve the clarity of the standard. The development of some of the equations were revised to better allow the user to understand the derivation of the equations. Also, it was determined that clearances between the ring and groove would be specified rather than fixed ring and fixed goove dimensions. This is more consistent with industry use of the standard.