The Shaft

 

Since the diameter of the shaft is smaller than that of the butt, Robinson puts the screw in the shaft, permanently filling the void that traditional shafts have, therefore making the shaft stronger and more stable. The 7/16 screw in the traditional shaft uses a hole 3/8" approximately 1" deep. The special hardend 5/16 screw used in the Robinson shaft goes 2" into the wood and because a smaller hole (1/4") is used, the screw displaces less wood adding to the shaft's strength and stability. This design has been very successful for over 30 years.