(someone) bring the hammer down

Translations
(кто-то) применяет строгие меры
The boss finally brought the hammer down on employees who were consistently late.
Босс наконец применил строгие меры к сотрудникам, которые постоянно опаздывали.
Definitions
To bring the hammer down means to take decisive, often harsh or authoritative action, especially to enforce rules or punish wrongdoing.