Question

_______________________ is a nut in which a collar is provided at the upper end of the hexagonal nut and a fiber ring is fitted inside it.

(a) Simmond’s locknut

(b) Penn nut

(c) Castle nut

(d) Sawn nut or wiles nut

The question was asked in an internship interview.

My question comes from Locking Arrangements for Nuts topic in chapter Screw Threads & Screwed Fastening of Engineering Drawing

Answer 1

The correct choice is (a) Simmond’s locknut

To explain: Simmond’s locknut is a nut in which a collar is provided at the upper end of the hexagonal nut and a fiber ring is fitted inside it. The internal diameter of ring is less than the core diameter of the bolt the end of the bolt, on reaching the ring, cuts its own thread in ring which prevents slacking.