Which fastener is described as a plan used with check nuts or lock washer?

• A. Nuts
• B. Non Self Locking Nuts
• C. Self Locking
• D. Plate Nut

Answer: (B)

When a fastener needs help staying tight in the face of vibration, you look at whether it locks on its own or relies on an extra retention method. A plain, non self-locking nut has no internal locking feature, so people add a lock washer or a jam/check nut to create the extra resistance needed to keep it from loosening. That matches the description of being used with check nuts or a lock washer. In contrast, self-locking nuts have a built-in locking mechanism and don’t depend on washers or jam nuts, and plate nuts are a different type used in specific assemblies. So the one described as used with check nuts or a lock washer is the plain, non self-locking nut.