指定方法的目的是通过切削工具获得可加工性的指示。该原理基于试件的完全燃烧，并在程序结束时称量干燥器中剩余的沙子。用于点燃试件的管状炉膛如图所示。

The purpose of the method specified is to obtain an indication of machinability by cutting tools. The principle is based on the complete combustion of test pieces and weighing the sand remaining in the desiccator at the end of the procedure. The tubular hearth used to ignite the test pieces is shown in the figure.