Gimlets are well known as convenient boring tools, and it is unnecessary to say anything about them except that there are two principal varieties, known as the shell and the twist gimlets, which are represented by Figs. 22 and 23. Either kind may be used, some preferring one and some the other. They are not required in large sizes.

Fig. 22 - Shell Gimlet.

Fig. 23. - Twist Gimlet.