Description / Abstract:
Differences, where they exist, are shown in Appendix A.
This SAE Standard specifies the essential dimensional features
of R, B, and M rectangular piston ring types with narrow ring
width.
Dimensional Tables 8 and 9 allow for the use of cast iron (Table
8) or steel (Table 9). Since the modulus of elasticity of steel
rings is higher than that of cast iron rings, the fluctuation in
the surface pressure will become greater if the free gap is set as
the reference for force. Therefore, forces are set using the
surface pressure as the reference, in order to minimize the effect
of the fluctuation.
The requirements of this document apply to rectangular rings for
reciprocating internal combustion engines up to and including 90 mm
diameter for cast iron rings and up to and including 100 mm
diameter for steel. They may also be used for piston rings of
compressors working under similar conditions.
Rationale—SAE J1998 is being discontinued
because the content of this standard is also contained in ISO
6622-2. Therefore, to eliminate duplication and confusion in
coordinating the standards between ISO and SAE, this document will
be discontinued. The SAE Piston and Ring Standards Committee will
now continue to support ISO in updating the standards as
appropriate.