ISO 7641:2012给出了一个简化的程序，用于根据UNECE《车辆构造统一决议》（R.E.3）中的规定，计算O1和O2类中轴挂车钢制牵引杆的机械强度，无论是否存在焊缝。因此，它仅适用于能够进行弯曲计算的简单结构。

ISO 7641:2012 gives a simplified procedure for the calculation of the mechanical strength of steel drawbars, whether there are welds or not, for centre-axle trailers Categories O1 and O2 as specified in the UNECE, Consolidated Resolution on the Construction of Vehicles (R.E.3). Consequently, it only applies to simple constructions that enable a calculation in bending.