3140 Steel Torsion Static Test 
3140 Steel Strain-hardening exponent versus true stress curve at 0.2 true strain 
The specimens assessed here are 2mm in diameter and 1mm in diameter, respectively. Size effect on the S-N curves can be found by comparing two figures.The trend of fatigue strength for diameter of 1 mm is lower than of 2 mm. Specimen size increase with decreasing in fatigue strength for all steel materials. Size coefficient is determined based on ratio of the fatigue strength of small-specimen with diameter 2 and 1 mm to fatigue strength of the normative specimen with diameter 8 mm. The size coefficient for specimen diameter of 2 mm is higher than that of 1m.
- ↑ J. Smith THE EFFECT OF RANGE OF STRESS ON THE TORSIONAL FATIGUE STRENGTH OF STEEL
- ↑ Y. Tamarin , Atlas of Stress-Strain Curves.ASM International. 2002 p.92
- ↑ 3.0 3.1 HAFTIRMAN, K. S. Basaruddin, M. Afendi and Syayuthi. A. R Assessment of Fatigue Strength in Small-specimen of AISI 3140 Steel. ICADME. 2015