A temporary shaft-component connection for assembling a selected golf club shaft with a club head and/or hand grip segment is disclosed to facilitate custom club design and fitting. The temporary shaft-component connection is designed for use with nonmetallic club shafts formed from a graphite-based composite material or the like having a range of different lengths and stiffness characteristics. In a shaft-head connection, a metal adapter insert is mounted onto a lower end of the club shaft and includes one or more flat surfaces for reception into a matingly shaped socket in the hosel of a selected club head to prevent relative rotation between the club shaft and head. A compression nut carried on the shaft is threaded onto the hosel to axially engage and retain a thrust flange on the shaft or adapter or adapter insert, to prevent axial separation of the club head and shaft.