Many excellent craftsmen are just deficient in imagination, lacking that one opportunity. Sometimes, a simple suggestion can spark their latent ideas.
Although threads have been used for a long time, their widespread use probably began after the Industrial Revolution when smelting technology for steel developed.
Without widespread use of steel, the development and application of threads were limited. Wooden tenon-and-mortise structures could solve many problems, so craftsmen never thought to put much effort into threads.
Ye Xinyan casually mentioned a few uses of threads, which greatly spurred the imagination of Zhang Mian and Wang Huan. The two were eager to try and wanted to thoroughly study the things Miss Ye had talked about and how they could be applied in practice. This was pioneering work, not just following rules and conventions, and if successful, they would become craftsmen of the Great Grandmaster level.
