Quality control of rolled threads

The thread quality and the microstructure and microhardness acquired as a result of machining by rolling are investigated. The characteristics, distribution, and depth of the deformed layer formed on rolling a threaded surface are established experimentally. The results indicate that rolling may expediently be used to improve the precision and surface roughness of thread and to increase the strength of the threaded joints. In many cases, it eliminates the need for subsequent heat treatment and grinding of the thread.