This SAE Recommended Practice describes the performance requirements for abrasion resistance of webbing when used in adjustment hardware normally used to adjust the length of seat belt assemblies such as those described in SAE J140. These requirements are applicable to tests conducted according to the procedure described in SAE J339. Although adjustment hardware is normally the primary source of webbing abrasion in a seat belt assembly, consideration should be given to other areas of normal webbing contact in the restraint system that may provide a more severe condition of webbing abrasion.
Seat belt webbing abrasion and tilt lock performance requirements are defined in SAE J114. The corresponding test methods are defined in SAE J339. Both these documents define abrasion and tilt lock testing for two point adjust tongues.
Two point adjust tongues are currently used in very few new passenger car and multi purpose vehicles. The FMVSS regulations only allow a 2 point belt at the front center seating position. Very few new vehicles have a front center seating position. Occupancy of this seating position, in the vehicles that have it, is low. As a result, abrasion from two point adjust tongues is not a concern in new vehicles.
Two point adjust tongues are more frequently used on off highway vehicles. Tilt lock and abrasion requirements for such vehicles are defined in SAE J386.
The scope of the SAE Belt Systems Standards Subcommittee is new passenger cars and multi purpose vehicles. For these vehicles, SAE J339 and SAE J114 are no longer required. For off road vehicles, that use 2 point adjust tongues, SAE J386 provides direction. Therefore it is proposed that SAE J114 and SAE J339 be changed to CANCELLED