J635_198407 FAN HUB BOLT CIRCLES AND PILOT HOLES

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.

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.