90/111 Center-Bit.] [Illustration: Fig.133.Foerstner Auger-Bit.] [Illustration: Fig.134. Expansive-Bit.] [Illustration: Fig.135. Reamer.] [Illustration: Fig.136.Rose Countersink.] _Gimlets_ and _drills_ are alike in that they cut away material, but unlike in that the cutting edge of the gimlet is on the side, while the cutting edge of the drill is on the end. 126, are very hard and may be used in drilling metal. They are therefore useful where there is danger of meeting nails, as in repair work. |