The aim of this paper is to analyze fatigue properties of high strength bolts in different metallurgical conditions. M8 bolts with coarse threads were separated in seven groups, three manufactured with AISI 4135 steel and heat treated after the process of thread rolling with three tempering temperatures (TRBHT). Four groups manufactured with SCM 435H steel and same conditions. In one group, the threads were made after quenching and tempering (TRAHT). Metallographic analyses, tension, hardness, and fatigue tests were performed. All TRBHT groups presented same fatigue resistance. TRAHT group presented fatigue limit approximately 9% superior than other groups. © 2011 Published by Elsevier Ltd.10 12971302Stephens, R.I., Bradley, N.J., Horn, N.J., Arken, J.M., Gradman, J.J., Influence of cold rolling threads before or after heat treatment on fatigue resistance of high strength coarse thread volts for multiple preload conditions (2006) J ASTM Inter, 3 (3)Kephart, A.R., Optimum thread rolling process that improves SCC resistance (2006) J ASTM Inter, 3 (7)Marcelo, A.L., (2008) Fatigue Properties of High Strength Bolts, , College of Mechanical Engineering, University of Campinas Dissertation (In Portuguese)Metallic materials-tensile testing at ambient temperature (1998) International Organization for Standardization, , ISO 6892 1998Threaded fastners-axial load fatigue testing-test methods and evaluation of results (1993) International Organization for Standardization, , ISO 3800 1993Ifergane, S., Eliaz, N., Stern, N., Kogan, E., Shemesh, G., Sheinkopf, H., Eleizer, D., The effect of manufacturing processes on fatigue lifetime of aeronautical bolts (2001) Eng Fail Anal, 8, pp. 227-235Mechanical properties of fastners made of carbon steel and alloy steel. Part 1: Bolts, screws and studs (1999) International Organization for Standardization, , ISO 898-1 1999