blunt instrument

noun
1
a heavy object without a sharp edge or point, used as a weapon
آلت ضربه‌ای, شیء کند, ابزار کند, شیء بی‌نوک
2
a way of doing something that is not efficient or not sensitive to people's feelings
وسیله غیرحساس, ابزار کم‌اثر, روش غیر دقیق
Low interest rates have become a blunt instrument for generating financial growth.