VEHICLE POWERTRAIN JOINTS COMPRISING SELF-TAPPING FASTENERS

摘要

A method for fastening components (18, 20) at critical joints in a motor vehicle powertrain. An unthreaded hole (22) is provided in a first component part (20), and a clearance hole (16) in a second component part (18). The shank (14) of a screw (10) that has a multi-lobed lead capable of creating a thread in the unthreaded hole is passed through the clearance hole to engage the multi-lobed lead with the unthreaded hole. Axial force and rotary torque are applied to the screw to cause the lead to form a desired helical thread in the unthreaded hole.