你方作为螺丝的专业厂家有义务保证螺丝的强度能满足标准的要求，因对于螺丝的强度我方无手段检测也没有义务检测，我们所能做的仅是检验螺丝的尺寸是否符合标准。这一点请务必清楚。 One point we should clarify that you as a professional manufacturer of screws, should ensure the strengh of the screws to meet the requirements of the corresponding standard. We have no instrument to do the test, furthermore, we have no obligation to do it. All we could do is just verify whether dimensions conform to the standard.