Drill bits are cutting tools used to create cylindrical holes, almost always of circular cross-section. Bits are held in a tool called a drill, which rotates them and provides torque and axial force to create the hole. Specialized bits are also available for non-cylindrical-shaped holes.
The shank is the part of the drill bit grasped by the chuck of a drill. The cutting edges of the drill bit are at one end, and the shank is at the other.
Drill bits come in standard sizes, described in the drill bit sizes article. A comprehensive drill bit and tap size chart lists metric and imperial sized drill bits alongside the required screw tap sizes.
The term drill may refer to either a drilling machine or a drill bit for use in a drilling machine. In this article, for clarity, drill bit or bit is used throughout to refer to a bit for use in a drilling machine, and drill refers always to a drilling machine.
Exceptionally, specially-shaped bits can cut holes of non-circular cross-section; a square cross-section is possible.
Other articles related to "drill bit, drill, bit":
... The impact of the drill bit fractures the rock and in many shale rock situations increases the water flow into a well over rotary ... well drilling and sometimes called "spudders", these rigs raise and drop a drill string with a heavy carbide tipped drilling bit that chisels through the rock ... The drill string is composed of the upper drill rods, a set of "jars" (inter-locking "sliders" that help transmit additional energy to the drill bit and assist in removing the ...
... A Drill bit, is a device attached to the end of the drill string that breaks apart, cuts or crushes the rock formations when drilling a wellbore, such as those drilled to extract water, gas ... The drill bit is hollow and has jets to allow for the expulsion of the drilling fluid, or "mud", at high velocity and high pressure to help clean the bit and, for softer formations, help to break ... A tricone bit comprises three conical rollers with teeth made of a hard material, such as tungsten carbide ...
... RC drilling is similar to air core drilling, in that the drill cuttings are returned to surface inside the rods ... is a pneumatic reciprocating piston known as a "hammer" driving a tungsten-steel drill bit ... ideally produces dry rock chips, as large air compressors dry the rock out ahead of the advancing drill bit ...
... Like in sludging, the drilling process is continuous the drill bit is normally not removed from the borehole until it is finished and the broken-up material is pumped to the surface in the drilling liquid (mud) ... of using a hand as a valve on top of the drill pipe (sludging), the drill bit itself doubles as a foot-valve ... The operator’s hand does not have to reach the end of the drill pipe and drill stem extensions can be several meters long ...
... The Tround Terra-drill is described in patent 4,004,642, issued to Dardick in 1977 ... The Terra-drill is a drill head that combines a traditional drill bit with the SALVO tround ... The tround is used to break through hard spots that the drill bit cannot readily penetrate ...
Famous quotes containing the words bit and/or drill:
“We must not leap to the fatalistic conclusion that we are stuck with the conceptual scheme that we grew up in. We can change it, bit by bit, plank by plank, though meanwhile there is nothing to carry us along but the evolving conceptual scheme itself. The philosophers task was well compared by Neurath to that of a mariner who must rebuild his ship on the open sea.”
—Willard Van Orman Quine (b. 1908)
“Swift blazing flag of the regiment,
Eagle with crest of red and gold,
These men were born to drill and die.
Point for them the virtue of slaughter,
Make plain to them the excellence of killing
And a field where a thousand corpses lie.”
—Stephen Crane (18711900)