This SAE Recommended Practice applies to fifth wheel kingpins for heavy-duty commercial trailers and semitrailers@ used for off-highway operation or in hauling heavy loads (see Figure 1).
SAE J848-2018 history
2018SAE J848-2018 Fifth Wheel Kingpin@ Heavy Duty - Commercial Trailers and Semitrailers
2011SAE J848-2011 Fifth Wheel Kingpin, Heavy-Duty Commercial Trailers and Semitrailers