Head pull-through properties of self-tapping screws

The head pull-through capacity Fhead is, together with the withdrawal capacity Fw, especially important for joints with screws as screws can transmit high axial forces. However, whereas Fw is always relevant for design, this is not the case for Fhead. If the head side member is made of e.g. steel, then – depending on the steel plate thickness – the screw head cannot be pulled through and either steel or withdrawal failure occurs.