The purpose of this SAE Recommended Practice is to encourage the standardization of mounting patterns for engine cooling fans as new engines are designed and developed in SI metric units. It is specifically not the objective of the specification to address the soft metric conversion of existing mounting patterns on engines designed in English units.
The scope of the specification is limited to heavy-duty diesel engine manufacturers, fan suppliers, and end users. Standard mounting patterns are given for fans up to 2000 mm rotating diameter. Passenger car and light-duty fans were not addressed because committee members issuing the specification felt that standards for these fans could be better addressed by personnel working in the market segments which use those fans. See Figure 1 and Table 1.
Rationale for issuance of the specification is cost savings through reduction of part numbers and inventory. Failure to comply with this specification will result in the need to release and carry in inventory parts of identical blade geometry and construction, but with different mounting patterns.