Machine Design - Study Mode

[#401] Castle nut is a locking device in which
Correct Answer

(D) Through slots are made at top and a cotter pin is passed through these and a hole in the bolt, and cotter pin spitted and bent in reverse direction at other end

[#402] When the length of the journal is equal to the diameter of the journal, then the bearing is said to be a
Correct Answer

(D) Square bearing

[#403] Factor of safety for fatigue loading is the ratio of
Correct Answer

(C) Endurance limit to the working stress

[#404] Crowning on pulley helps
Correct Answer

(C) To keep the belt in centre on a pulley while it is in motion

[#405] A bench vice has following type of threads
Correct Answer

(C) Buttress

Explanation

Solution: A bench vice is a mechanical device used for holding and clamping workpieces securely in place during various machining operations. The vice is equipped with a threaded screw mechanism that allows the jaws of the vice to move closer together or farther apart. The type of threads used in the bench vice's screw mechanism determines its efficiency and load-bearing capacity. Among the options provided, the correct answer is Option C: Buttress . A bench vice often employs a buttress thread mechanism. Buttress threads have one side with a steep angle (known as the "serrated" side) and another side with a flat or slightly angled surface. This design provides efficient load-bearing capability in one direction while allowing quick return travel in the opposite direction. Buttress threads are particularly suitable for applications where high axial loads are involved. Therefore, the correct answer is Option C: Buttress .