The purpose of this recommended practice is to establish test procedures and minimum performance standards for kingpins manufactured to SAE specifications. The inspection gage will permit the establishment of standard clearances in the installed condition which@ in turn@ will permit fifth wheel manufacturers to design their products to establish interchangeably with any kingpin made and installed to the SAE specification.
SAE J133-1970 history
2011SAE J133-2011 Fifth Wheel Kingpin Performance Commercial Trailers and Semitrailers
2003SAE J133-2003 (R) Fifth Wheel Kingpin PerformanceCommercial Trailers and Semitrailers