Section § 393.70: Coupling devices and towing methods, except for driveaway-towaway operations.

Guidance Q&A

Question 1: Is there a minimum number of fasteners required to fasten the upper fifth wheel plate to the frame of a trailer?

Guidance: The FMCSRs do not specify a minimum number of fasteners. However, the industry recommends that a minimum of ten 5/8 inch bolts be used. If ½ inch bolts are used, the industry recommends at least 14 bolts. The CVSA has adopted these industry standards as a part of its vehicle out-of-service criteria.