VEHICLE POWERTRAIN JOINTS COMPRISING SELF-TAPPING FASTENERS

摘要

A method for fastening components ( 18, 20 ) at critical joints in a motor vehicle powertrain ( 24 ). 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.