What is "twist drill"

Twist \Twist\, n.

1. The act of twisting; a contortion; a flexure; a convolution; a bending.

   Not the least turn or twist in the fibers of any one animal which does not render them more proper for that particular animal's way of life than any other cast or texture.
   --Addison.

2. The form given in twisting.

   [He] shrunk at first sight of it; he found fault with the length, the thickness, and the twist.
   --Arbuthnot.

3. That which is formed by twisting, convoluting, or uniting parts. Specifically:

   1. A cord, thread, or anything flexible, formed by winding strands or separate things round each other.

   2. A kind of closely twisted, strong sewing silk, used by tailors, saddlers, and the like.

   3. A kind of cotton yarn, of several varieties.

   4. A roll of twisted dough, baked.

   5. A little twisted roll of tobacco.

   6. (Weaving) One of the threads of a warp, -- usually more tightly twisted than the filling.

   7. (Firearms) A material for gun barrels, consisting of iron and steel twisted and welded together; as, Damascus twist.

   8. (Firearms & Ord.) The spiral course of the rifling of a gun barrel or a cannon.

   9. A beverage made of brandy and gin. [Slang]

4. [OE.; -- so called as being a two-forked branch. See Twist, v. t.] A twig. [Obs.]
   --Chaucer. Fairfax.

5. Act of imparting a turning or twisting motion, as to a pitched ball; also, the motion thus imparted; as, the twist of a billiard ball.

6. A strong individual tendency, or bent; a marked inclination; a bias; -- often implying a peculiar or unusual tendency; as, a twist toward fanaticism.

   Gain twist, or Gaining twist (Firearms), twist of which the pitch is less, and the inclination greater, at the muzzle than at the breech.

   Twist drill, a drill the body of which is twisted like that of an auger. See Illust. of Drill.

   Uniform twist (Firearms), a twist of which the spiral course has an equal pitch throughout.

n. A rotate cutting tool, used for cutting holes in rigid materials, that consists of an essentially cone point, relieved and fluted to form cutting lips, and spiral flutes which direct the chips away from the lips and toward ejection from the hole.

n. a bit or drill having deep helical grooves [syn: twist bit]