Effect of thread cutting techniques on the fatigue and corrosion-fatigue strength of steel

The influence of single and multiple grooves and threads M10 × 1.5 and M10 × 1.0 on the fatigue strength of steel in air and in a 3% NaCl solution was demonstrated. It was established that specimens with a single groove or with a thread produced by thread-forming rolls have the maximum fatigue and corrosion-fatigue strength; this is due to the optimum physico-mechanical properties conferred on the metal by the groove or thread producing operations. The effect of the method of producing stress raisers on the relief of stress concentration due to a change over from a single groove to multiple grooves or to a thread was determined.