Within the mechanical industry, inch-based spare parts can occasionally be kept, e.g., to service American or pre-World War II machines, but at maintenance, screws may be exchanged to metric thread.
在机械行业，基于英寸的备件偶尔得以保留，例如为了保养美式或二战前的机器，但在维护中螺丝可能换为ISO公制螺纹规格。