Abstract: A releasable fastening structure for quick assemblage and disassemblage of golf clubs and shafts for trial purposes provides club heads with hosels carrying diametrically extending fastening pins to interconnect with cooperating shafts defining fastenably interconnecting channels. The head end portion of cooperating shafts define "U" shaped channels to receive the fastening pin in releasable interconnection upon axial and rotary motion in the hosel channel. A spring in the hosel channel inwardly of the fastening pin biases a shaft therein outwardly to maintain fastenable interconnection after establishment, but allows manually generated, axially inward motion for quick assembly and disassembly.