The M-40 Standard Metric Rod has the sturdiness suitable for the majority of general laboratory applications. Made entirely of steel, it has a 38.1 mm diameter and is 356 mm tall. Steel provides much greater dynamic rigidity than aluminum due to its almost order-of-magnitude greater material loss factor. This means the M-41 rod has a high resonant frequency and correspondingly low vibration amplitude required for optical laboratory use. Also, with its inherently greater stiffness and strength, it supports larger loads with greater stability. Steel construction has other advantages; steel has half the thermal expansion coefficient of aluminum and a higher heat capacity so thermal stability is enhanced.


M-40标准米制棒具有适用于大多数一般实验室应用的坚固性。全钢制造，直径38.1毫米，高356毫米。钢比铝提供更大的动态刚度，因为它几乎数量级更大的材料损失因子。这意味着M-41杆具有较高的谐振频率和相应的较低的振幅，需要光学实验室使用。同时，由于其固有的更大的刚度和强度，它支持更大的负载和更大的稳定性。钢结构还有其他优点;钢的热膨胀系数是铝的一半，热容较高，热稳定性增强。