ESDU 13016 discusses the behaviour of loads in a pre-loaded@ single-bolt joint during external loading. Using a non-linear finite element analysis of the bolt and the member@ loads are plotted against applied external loading@ ranging from zero (bolt pre-loaded only) up to a maximum of 0.95 times the amount of pre load; note the data are non dimensionalised with respect to pre-load. The effect of bolt size@ joint geometry@ radial position of the external load@ material properties in the joint and thread flexibility on the loads are all examined. The Item also considers changes to the inter-member contact pressure distributions that take place in a reference joint. The relationship between member stiffnesses and the applied external load is examined with a worked example calculating bolt and member stiffnesses when external loads are applied to an M10 bolted joint.