Fatigue strength of large diameters tension rods with metric cut thread

The present paper deals with the fatigue strength of large diameters tension rods with metric, cut thread of S460N steel grade. In total 36 fatigue tests equally categorised to 4 experimental series with two varying parameters (i) size diameter, M68 and M100, and (ii) surface treatment, hot-dip galvanized or as-rolled, were performed by the Institute of Structural Design at the Material Testing Institute of the University of Stuttgart. The tests conducted herein for rods of metric, cut threads validated the detail category 50 as well as its factor for size effect, while being slightly on the safe side.Additionally, one specimen of M100 as-rolled tension rods, equipped with six miniature strain gauges placed on the thread root of the upper tension rod was tested up to 4,8 MN of quasi-static monotonic tension load- ing until complete failure. Strain concentration factors for the thread root of the M100 tension rod were calculated.