Abstract
It is natural that the roughness of machined surface has much to with capacity, durability, appearance etc. of machinery. With the progress of machining technique, the standardization of surface roughness has become necessary, which many countries in the world have already established.
But it is so troublesome and tedious to measure the surface roughness with surface-roughness-tester, that the so called surface-roughness-scale with which we can find out the roughness of the surface macroscopically or by touching has more and more been called for.
Complying with the requirement, the authers manufactured roughness mother plates of various kinds of machining, and they also studied how far the limits of the roughness of every machining are.
