Ah, you're asking about "缩孔" in English, huh? Well, let me try to... um, translate that for you. "缩孔" can be a bit... ambiguous. If it's about making a hole smaller, you might say "reduction of hole diameter" or "shrinkage of the hole." But if it's a term from a specific context, like manufacturing or engineering, it could have a more... specific translation. Like, "hole reduction" or "hole sizing down." Just depends on what exactly you're talking about, you know?
Contraction in hole
Coning