At what percentage of thread engagement is maximum strength reached?

Maximum strength is typically reached at a thread engagement of around 75 percent. When threads are engaged to this extent, the load is effectively distributed across the thread surfaces, enhancing the overall friction and resistance to stripping and failure.

While the engaged percentages of 50 percent, 60 percent, and 65 percent can still provide acceptable performance, they do not optimize the strength of the joint as effectively as 75 percent engagement. In threaded connections, achieving the right amount of engagement is crucial, as insufficient engagement can lead to weaker joints and premature failure under load.

Therefore, the notion that 60 percent engagement achieves maximum strength is closer to the right concept, but the effective design standard falls on the side of full engagement around 75 percent for achieving optimal performance in threaded connections.