differences-between-turning-groovesTurning grooves on a clampbolt made from Waspalloyca. 0.1 mmParallel cracks in the turning grooves Crack parallel to prim-ary fracture surfacePrimary fracture surfaceSharp notch baseof turning groovesTurning grooves are not all the same, even ifthey have the same depth! Sharply-cut notch bases should have apronounced weakening effect on the dynamicfatigue strength. Additional effects that can be expected:- Low residual stresses or tensile residual stresses- Minimal hardeningRounded notch bases should only have a minor negative effect on thedynamic fatigue strength. Additionaleffects that can be expected:- Compressive residual stresses- Considerable hardening