What feature is typically used in an elastic nut for securing bolt threads?

• A. A small nut tightened over the main nut
• B. Hard fiber or nylon cotter recessed in the nut
• C. Slots cut in the nut
• D. A through bolt with a cotter pin

Answer: (B)

The feature typically used in an elastic nut for securing bolt threads is a hard fiber or nylon cotter recessed in the nut. This design element ensures that the nut can maintain tightness even when subjected to vibrations or changes in torque, enhancing its effectiveness in securing the bolt threads. The use of materials such as nylon allows for frictional resistance, which prevents loosening. A recessed cotter can also provide an additional mechanical locking element by engaging the threads of the bolt, contributing to the overall reliability of the connection.

In contrast, other options, while they involve different methods of securing mechanically fastened connections, do not represent the standard feature of an elastic nut. For instance, a small nut tightened over the main nut does not provide the same kind of internal locking mechanism that characterizes an elastic nut. Slots cut in the nut might be used for other types of fasteners but do not effectively provide the locking needed in this context. A through bolt with a cotter pin generally refers to a different assembly style where the pin holds the bolt in place rather than securing the threading itself.