1990-1998 Arctic Cat Snowmobiles Repair Manual, Page 20Get this manual
CHAPTER ONE
bolts are described by the diameter and pitch (the distance between each thread)
measurement across two flats on the nut indicates the proper wrench size to be usedSelf-Locking Fasteners Several types of bolts, screws and nuts incorporate system that develops an interference between the bolt, screw, nut or tapped hole threadsInterference is achieved in one of the following ways: by distorting threads, coating threads with dry adhesive or nylon, distorting the top of an all-metal nut or using nylon insert in the center or at the top of nutSelf-locking fasteners offer greater holding strength and better vibration resistanceSome self-locking fasteners can be reused if they are in good conditionOthers, like the nylon insert nut, form an initial locking condition when the nut is first installedThe nylon forms closely to the bolt thread pattern, thus reducing any tendency for the nut to loosenWhen the nut is removed, the