A child using a cordless handheld drill to assemble a bookcase.

A drill (from Dutch Drillen) is a tool with a rotating drill bit used for drilling holes in various materials. A broader definition of a tool is an entity used to interface between two or more domains that facilitates more effective action of one domain upon the other For the ficitonal character see Drill Bit (Transformers. Drill bits are cutting tools used to create cylindrical holes Drilling is the process of using a Drill bit in a Drill to produce cylindrical holes in solid materials such as wood or metal Drills are commonly used in woodworking, metalworking, construction and DIY. Woodworking is the process of building making or carving something using Wood. Metalworking is craft and practice of working with Metals to create individual parts assemblies or large scale structures Some mistakenly call it a drill motor which is actually the motor inside the drill.

The drill bit is gripped by a chuck at one end of the drill, and is pressed against the target material and rotated. A chuck is a specialised type of clamp used to hold rotating tools or materials The tip of the drill bit does the work of cutting into the target material, either slicing off thin shavings (twist drills or auger bits), grinding off small particles (oil drilling), or crushing and removing pieces of the workpiece (SDS masonry drill).

History

The earliest drills were bow drills which date back to the ancient Harappans and Egyptians. The bow drill is an ancient Tool. While it was usually used to make Fire, it was also used for primitive Woodworking and Dentistry. The Indus Valley Civilization (Mature period 2600&ndash1900 BCE abbreviated IVC, was an ancient Civilization that flourished in the Indus River basin Ancient Egypt was an Ancient Civilization in eastern North Africa, concentrated along the lower reaches of the Nile River in what is now The drill press as a machine tool evolved from the bow drill and is many centuries old. It was powered by various power sources over the centuries, such as human effort, water wheels, and windmills, often with the use of belts. This article is about a type of structure For other locational uses see Milldam. A windmill is a machine that is powered by the energy of the wind A Belt is a looped strip of flexible material used to mechanically link two or more rotating shafts With the coming of the electric motor in the late 19th century, there was a great rush to power machine tools with such motors, and drills were among them. The invention of the first electric drill is credited to Mr. Arthur James Arnot and William Blanch Brain ^[1], in 1889, at Melbourne, Australia. Year 1889 ( MDCCCLXXXIX) was a Common year starting on Tuesday (link will display the full calendar of the Gregorian calendar (or a Common Melbourne ( is the second most populous city in Australia, with a Metropolitan area population of approximately 3 Wilhelm Fein^[2] invented the portable electric drill in 1895, at Stuttgart, Germany. Year 1895 ( MDCCCXCV) was a Common year starting on Tuesday (link will display full calendar of the Gregorian calendar (or a Common year Stuttgart (ˈʃtʊtgaɐ̯t is the capital of the state of Baden-Württemberg in southern Germany. In 1917, Black & Decker patented a trigger-like switch mounted on a pistol-grip handle. Year 1917 ( MCMXVII) was a Common year starting on Monday (link will display the full calendar of the Gregorian calendar (or a Common year Black & Decker Corporation ( is a Corporation based in Towson Maryland, that makes and markets Power tools and accessories hardware ^[3]

Types

The inside of a electric drill

There are many types of drills: some powered manually, others using electricity or compressed air as the motive power, and a minority driven by an internal combustion engine (for example, earth drilling augers). The internal combustion engine is an engine in which the Combustion of Fuel and an Oxidizer (typically air occurs in a confined space called a Drills with a percussive action (such as hammer drills, jackhammers or pneumatic drills) are usually used in hard materials such as masonry (brick, concrete and stone) or rock. A Hammer drill, also known as a "rotary hammer" or "roto-hammer" (see also rotary hammer drill) is a rotary Drill with a hammering action A pneumatic drill or jackhammer is a portable percussive Drill powered by Compressed air. Masonry is the building of structures from individual units laid in and bound together by mortar, and the term "masonry" can also refer to the units themselves In Geology, rock is a naturally occurring aggregate of Minerals and/or Mineraloids The Earth's outer solid layer the ‘ Lithosphere Drilling rigs are used to bore holes in the earth to obtain water or oil. For a detailed diagram of a Petroleum drilling rig, See Drilling rig (petroleum A drilling rig is a machine which creates holes (usually called An oil well, water well, or holes for geothermal heating are created with large drill rigs up to a hundred feet high. West Texas PumpjackJPG|thumb|right|300px|This Pumpjack located south of Midland TX is a common sight in West Texas. Geothermal heating has been used since the time of the Roman Empire as a way of heating Buildings and Spas by utilizing sources of hot Water Some types of hand-held drills are also used to drive screws. A screw is a shaft with a helical groove or thread formed on its surface and provision at one end to turn the screw Some small appliances may be drill-powered, such as small pumps, grinders, etc.

Carpenter using a crank-powered brace to drill a hole. A brace or brace and bit is a Hand tool used to Drill holes usually in Wood.

Hand tools

A variety of hand-powered drills have been employed over the centuries. Here are a few, starting with approximately the oldest:

• Bow drill
• Brace and bit
• Gimlet
• Breast drill, also known as "eggbeater" drill
• Push drill, a tool using a spiral ratchet mechanism
• Pin chuck, a small hand-held jewellers drill

An old hand drill or "eggbeater" drill

Pistol-grip (corded) drill

A drill in the shape of a pistol is today a useful and ubiquitous type of power tool. The bow drill is an ancient Tool. While it was usually used to make Fire, it was also used for primitive Woodworking and Dentistry. A brace or brace and bit is a Hand tool used to Drill holes usually in Wood. A gimlet is a Hand tool for Drilling small holes mainly in wood without splitting In Mechanical engineering, a ratchet is a device that allows linear or rotary motion in only one direction while preventing motion in the opposite direction A pin chuck is a small work holding device It is often used to hold small drills (<1 mm that would not be held securely in a normal (1 mm&ndash13 mm drill chuck A power tool is a Tool powered by an Electric motor, a compressed air motor or a gasoline engine There is an endless variety of subtypes of this basic form factor, with the notable exception being the Right Angle Drill, a specialty tool used by trade specialists such as plumbers and electricians.

Hammer drill

The hammer drill is similar to a standard electric drill, with the exception that it is provided with a hammer action for drilling masonry. A Hammer drill, also known as a "rotary hammer" or "roto-hammer" (see also rotary hammer drill) is a rotary Drill with a hammering action The hammer action may be engaged or disengaged as required.

The hammer action is provided by two cam plates which makes the chuck rapidly pulse forward and backward as the drill spins on its axis. This pulsing (hammering) action is measured in Blows Per Minute (BPM) with 10,000 or more BPMs being common. Because of the relative masses of the chuck+bit and the remainder of the drill the energy transfer is relatively inefficient and can sometimes make it difficult for larger bits to penetrate harder materials such as poured concrete. Vibration is quite noticeable by the operator, and the cams are generally made from hardened steel to avoid them wearing out quickly. Most electic hammer drills are rated at between 6. 3 and 9 amps, and are restricted to standard masonary bits 1/2 inch in size maximum. A typical application for a hammer drill would be to install electrical boxes, conduit straps or shelves in concrete.

Compare this to a rotary/pneumatic hammer drill where just the bit is accelerated to the work. This is accomplished through a piston design, rather than a spinning cam. Rotary hammers have relatively little vibration and penetrate most building materials. They can also be used as "drill only" or as "hammer only" which extends their usefulness for tasks such as chipping brick or concrete. Hole drilling progress is greatly superior to cam type hammer drills, and these drills are generally used for holes of 3/4 an inch or greater in size. A typical application for a rotary hammer drill would be to bore large holes for lag bolts in foundations, or to install large lead anchors in concrete for handrails or benches.

A standard hammer drill accepts 1/4 inch and 1/2 inch drill bits, while a rotary hammer uses SDS or Spline Shank bits. A chuck is a specialised type of clamp used to hold rotating tools or materials These heavy bits are adept at pulverising the masonry and drill into this hard material with relative ease.

However there is a big difference in cost. In the UK typically £12 upward for a cam hammer and £35 up for a rotary/pneumatic. In the US a typical hammer drill will cost between $70 and $120, and a rotary hammer between $150 and $500 (depending on bit size). For DIY use or to drill holes less than 1/2 inch in size, the hammer drill is most commonly used.

Rotary hammer drill

The rotary hammer drill (also known as roto hammer drill or masonry drill) is an electric drill type dedicated to drilling holes in masonry. The rotary hammer drill is a percussion drill that uses a weight to create the impact force on the masonry bit. Generally, the drill chuck of the rotary hammer drill is designed to hold SDS drill bits. Some styles of this drill are intended for masonry drilling only and the hammer action cannot be disengaged. Other styles allow the drill to be used without the hammer action for normal drilling, or hammering to be used without rotation for chiselling.

Cordless drills

A cordless drill with clutch

A cordless drill is a type of electric drill which uses rechargeable batteries. See also Rechargeable electricity storage system A rechargeable battery, also known as a storage battery, is a group of two or more secondary These drills are available with similar features to an AC mains-powered drill. An alternating current ( AC) is an Electric current whose direction reverses cyclically as opposed to Direct current, whose direction remains constant They are available in the hammer drill configuration and most also have a clutch setting which allows them to be used for driving screws. Also available now are Right Angle Drills, which allow a worker to drive screws in a tight space. These are currently less useful than the corded version however, as one of the main functions is drilling holes through joist and studs to run electrical and plumbing. While recent battery innovation allows significantly more drilling, the large diameter holes required (typically 1/2"-1" or larger)drain current cordless drills quickly.

For continuous use, a worker will have one or more spare battery packs charging while drilling, so that he or she can quickly swap them, instead of having to wait an hour or more for recharging. Although there are now Rapid Charge Batteries that can charge in 10-15 minutes.

Early cordless drills started with interchangeable 7. 2V battery packs, and over the years available battery voltages have increased, with 18V drills being most common, and 24V drills are available. The volt (symbol V) is the SI derived unit of electric Potential difference or Electromotive force. This allows these tools to produce as much torque as some mains-powered drills. The drawback of most current models is the use of nickel-cadmium (NiCd) batteries, which have limited life, self discharging and eventually internally short circuiting due to dendrite growth. The nickel-cadmium battery (commonly abbreviated NiCd and ˈnɑɪˌkæd "nye-cad" is a type of Rechargeable battery using Nickel oxide hydroxide Short Circuit is a 1986 comedy Science fiction film starring Ally Sheedy and Steve Guttenberg and directed by A dendrite in Metallurgy is a characteristic tree-like structure of Crystals growing as molten metal freezes the shape produced by faster growth along energetically This severely limits battery life, and poses a hazardous materials disposal problem. A dangerous good is any Solid, Liquid, or Gas that can harm people other living Organisms property or the environment A lot of Drill manufacturers, including DeWalt, Ryobi, and Ridgid, are now using lithium ion batteries. Lithium-ion batteries (sometimes abbreviated Li-ion batteries) are a type of Rechargeable battery in which a Lithium ion moves between the Anode The main advantages are very short charging time, longer life, and lighter battery weights. Instead of charging a tool for an hour to get 20 minutes of use, 20 minutes of charge can run the tool for an hour. Lithium-ion batteries also have a constant discharge rate. The power output remains constant until the battery is depleted, something that nickel-cadmium batteries also lack, and which makes the tool much more versatile. Lithium-ion batteries also hold a charge for a significantly longer time than nickel-cadmium batteries, about 2 years if not used, vs. 1 - 4 months for a nickel-cadmium battery.

The handle of cordless drills are usually made from polymorph which is easy and quick to mold to a comfortable shape for holding. The main body of the drill is usually made from polythene as it is able to withstand the high temperatures which the drill reaches.

Drill press

A drill press.

A drill press (also known as pedestal drill, pillar drill, or bench drill) is a fixed style of drill that may be mounted on a stand or bolted to the floor or workbench. A workbench is sturdy table at which manual work is done They range from simple flat surfaces to very complex designs that may be considered tools in themselves A drill press consists of a base, column (or pillar), table, spindle (or quill), and drill head, usually driven by an induction motor. A router is a Woodworking Tool used to rout out (hollow out an area in the face of a piece of Wood. An electric motor uses Electrical energy to produce Mechanical energy. The head has a set of handles (usually 3) radiating from a central hub that, when turned, move the spindle and chuck vertically, parallel to the axis of the column. The table can be adjusted vertically and is generally moved by a rack and pinion; however, some older models rely on the operator to lift and reclamp the table in position. A rack and pinion is a pair of Gears which convert rotational motion into linear motion The table may also be offset from the spindle's axis and in some cases rotated to a position perpendicular to the column. The size of a drill press is typically measured in terms of swing. Swing is defined as twice the throat distance, which is the distance from the center of the spindle to the closest edge of the pillar. For example, a 16-inch drill press will have an 8-inch throat distance.

A drill press has a number of advantages over a hand-held drill:

• less effort is required to apply the drill to the workpiece. The movement of the chuck and spindle is by a lever working on a rack and pinion, which gives the operator considerable mechanical advantage. In Physics and Engineering, mechanical advantage (MA is the factor by which a mechanism multiplies the force put into it
• the table allows a vise or clamp to position and lock the work in place making the operation much more secure. A vise or vice (see under miscellaneous spelling differences) is a mechanical Screw apparatus used for holding or clamping a work piece to allow work to A clamp is a fastening device to hold or secure objects tightly together to prevent movement or separation through the application of inward Pressure.
• the angle of the spindle is fixed in relation to the table, allowing holes to be drilled accurately and repetitively.

Speed change is achieved by manually moving a belt across a stepped pulley arrangement. A pulley (also called a sheave or block) is a Wheel with a groove between two Flanges around its Circumference Some drill presses add a third stepped pulley to increase the speed range. Modern drill presses can, however, use a variable-speed motor in conjunction with the stepped-pulley system; a few older drill presses, on the other hand, have a sort of traction-based continuously variable transmission for wide ranges of chuck speeds instead, which can be changed while the machine is running. A continuously variable transmission ( CVT) is a transmission which can change steplessly through an infinite number of effective gear ratios between maximum

Geared head drill

The geared head drill is identical to the drill press in most respects, however they are generally of sturdier construction and often have power feed installed on the quill mechanism, and safety interlocks to disengage the feed on overtravel. The most important difference is the drive mechanism between motor and quill is through a gear train (there are no vee belts to tension). This makes these drills suitable for use with larger drill bits.

Radial arm drill

A radial arm drill is a geared head drill that can be moved away from its column along an arm that is radiates from the column. These drills are used for larger work where a geared head drill would be limited by its reach, the arm can swivel around the column so that any point on the surface of the table can be reached without moving the work piece. The size of work that these drills can handle is considerable as the arm can swivel out of the tables area allowing an overhead crane to place the workpiece on the fixed table. Vises may be used with these machines but the work is generally bolted to the table or a fixture.

Mill drill

Mill drills are a lighter alternative to a milling machine. A milling machine is a Machine tool used for the shaping of Metal and other Solid Materials. They combine a drill press (belt driven) with the X/Y coordinate abilities of the milling machine's table and a locking collet that ensures that the cutting tool will not fall from the spindle when lateral forces are experienced against the bit. Although they are light in construction, they have the advantages of being space-saving and versatile as well as inexpensive, being suitable for light machining that may otherwise not be affordable.

Other tools that sometimes drill holes

• Milling machines, metal lathes and routers are also often used for drilling. A milling machine is a Machine tool used for the shaping of Metal and other Solid Materials. Metal lathe or metalworking lathe are generic terms for any of a large class of Lathes designed for precisely Machining relatively A router is a Woodworking Tool used to rout out (hollow out an area in the face of a piece of Wood.

See also

• Auger
• Boring (mechanical)
• Bow drill
• Core drill
• Drill bit
• Seed drill
• Well drilling
  • Oil well

References

External links

• Nonfatal Occupational Injuries Involving the Eyes - From US Department of Labor (Accessed 2007-04-29)
• Blog and Podcast on Drills hosted by The Handyguys Podcast