In the same material, dimension and load circumstance, the cut stress of the triangle thread is smallest. Its ruptureload is higher than the echelon and rectangle.
The methods of creep test to get both curves of tensile creep ruptureload vs time and creep strain vs time are compared. The procedures to extrapolate the two types of creep curves are presented.
It was also found that at a fixed temperature the transverse-rupture strength of the alloy generally increased with the steepness of load-deflection curves.