How do drills work?

Answer 1

A drilling machine is able to hold a certain diameter of drill(in what is known as a chuck), and rotates at a specified rpm(revolutions per minute) enabling the drill to start a hole. the rpm of a drill is calculated by: cutting speed divided by the diameter of the drill times 300.

If the question is regarding oil & water well drilling machinery - it's a little more complicated. Typically, oil, gas, and water wells are drilled using what is called a 'mud rotary' system. A drill rig with a derrick suspends the drill pipe (20-30ft long tubes made of steel that a threaded together) inside the bore hole. A drill bit is attached to the other end. They then rotate this assembally inside the hole & let the weight of the bit & drill pipe settle on the bottom & cut the material from the bottom of the hole. A drilling fluid is pumped down the drill pipe and out the end of the bit, from there the fluid circulates back up to the surface, and is either disposed of (when using air as a fluid) or recycled & cleaned to go back down the bore hole. The fluid acts as a cooling agent for the bit, and also suspends & lifts all the cuttings out of the hole, allowing the bit to cut more material from the bottom.

Typically, smaller mobile drill rigs weigh in excess of 50,000 lbs, have 35ft derricks, and use 20ft drill pipe segments to drill with. They can be delivered with on board compressors that deliver up to 1070 cubic feet per minute of air at 350 psi, and/or mud pumps that pump hundreds of gallons of mud slurry per minute at very high pressures (500 psi +-). The derricks are usually able to hold 30,000lbs or more of drill rod & bits in the hole. A 4.5" diameter drill pipe, 20' long, with a 3.5" ID, weighs approximately 360lbs - so a 3000' hole can have up to 150 drill pipes, plus bit & stabilizers, weighing in excess of 54,000lbs.

Answer 2

drilling action starts with extrusion, i.e it enters with force, once it enter, the two cutting edges do actual cutting action, while grooves around body of drill helps the already cut chip to get out for smooth cutting.