Which feature enables assembly and disassembly of a screwed coupling?

• A. Threads
• B. Bolts
• C. Snap rings
• D. Keys

Answer: (A)

Threads enable a screwed coupling to be assembled and disassembled. In a screwed coupling, one part has external threads and the other has internal threads. When you rotate the pieces, the threads engage and draw the parts together to form a tight, removable connection. The thread pitch governs how far the parts move with each turn, so you can tighten for a secure fit or back off to disassemble. This reversible nature is what makes a screwed coupling specifically reliant on threaded engagement.

Other mechanisms don’t provide this same threaded connection: bolts need a nut and aren’t the built-in joining feature of a screwed coupling; snap rings hold parts in place without threading; keys transmit torque between a shaft and a rotating member and don’t enable reversible assembly through turning.