A screw auger has a twisted blade, by the spiral groove of which the chips are discharge. Webster's Unabridged Dictionary (2nd 100 Pages) 2012-03-24T02:00:19.387Z
Fortunately I had purchased at Khartoum an English screw auger 1 1/4 inch in diameter, and this tool I had brought with me, foreseeing some difficulties in boating arrangements. The Albert N'Yanza, Great Basin of the Nile