The 72 Extra Long Standard Rod has the sturdiness suitable for the majority of general laboratory applications. Made of steel, it has a 1.5 inch (38.1 mm) diameter and is 24 inch (610 mm) tall with a nylon gear rack set into the rod for rack-and-pinion control over component elevation. Steel provides much greater dynamic rigidity than aluminum due to its almost order-of-magnitude greater material loss factor. This means this 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.


72超长标准棒具有坚固性，适用于大多数一般实验室应用。它由钢铁制成，直径1.5英寸(38.1毫米)，高24英寸(610毫米)，杆上装有尼龙齿轮架，用于机架和小齿轮控制组件的高度。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。这意味着该杆具有较高的谐振频率和相应的光学实验室使用所需的低振动振幅。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。