You Know the Drill
The drill is one of the oldest—and most common—tools known to humankind. After rocks and clubs were first used to pound things, along came tools for cutting material away from objects (axes, knives) and cutting into workpieces (awls, saws). The first drills were simply pointed rocks or wooden sticks that the user spun between his or her hands with a downward pressure into a primitive workpiece to make a hole or start a fire. Eventually it was discovered that using straps of leather, cloth, or rope wrapped around a stick (creating a bow drill), two workers could generate more torque to make deeper holes in harder substances.
As metal processing and other technology progressed over the millennia, drills became more and more sophisticated as well, being able to be utilized in a variety of industries. While drills are found throughout the modern world in everything from woodworking to dentistry to oilfield work, our focus today is on metal drilling machines and their role in the realms of machining and fabrication.
History of Metalworking Drills
Early drills were used on materials such as wood, leather, bone, antlers, ivory, shells, and even teeth. Drilling rocks came later, first with labor intensive wooden drills, then eventually using metal ones. Once drills started to be made of metal, craftsmen found they could drill into softer metals with them.
The big technological leap came with the application of the electric motor to drilling machines in the late nineteenth century and the invention of the drill press. Some key events in the history of modern drills are the following:
- 1889 | Arthur James Arnot and William Blanch Brain of Australia patented the electric drill.
- 1895 | Wilhelm Emil Fein and his brother Carl invented the first portable handheld drill in Germany.
- 1917 | Americans Duncan Black and Alonzo Decker, inspired by the design of a colt pistol, patented the first portable drill with a pistol grip and a trigger switch.
- 1918 | Henry Ford asked Arno H. Petersen, a tool and die maker, to develop a lightweight drill for use in automotive production lines. Three years later, Arno patented a five-pound one-handed portable drilled called the Hole-Shooter. After his facility burned down, the Milwaukee Electric Tool Company acquired the product and made improvements on it.
- 1921 | The Black & Decker company began advertising their portable electric drill to the public instead of just to industries. Two years later it introduced a low-priced version created specifically for nonprofessionals.
- 1932 | The Bosch company introduced a handheld electropneumatic rotary hammer.
- 1942 | A month after the attack on Pearl Harbor, U.S. President Franklin D. Roosevelt ordered the establishment of the War Production Board, one purpose of which was to convert peacetime factories into manufacturing plants for the war effort. Metalworking drills, which were in common use by this time in the manufacture of appliances and automobiles, were adapted to mass produce items like guns, tanks, and aircraft.
- 1946 | Black & Decker produced the first line of home power tools, including drills and accessories.
- 1961 | Black & Decker manufactured the first cordless drill, powered by a rechargeable nickel cadmium (NiCad) battery.
- 1980s | The variable-frequency drive (VFD) goes into widespread use in the machine tool industry. Variable speed drills previously required an operator to manually adjust a belt and pulley system to alter the gear ratio of the machine to change drilling speeds. Drills equipped with a VFD could now change speeds at the turn of a knob.
- 2005 | The Milwaukee company invented technology that allowed them to use lithium-ion batteries in their power tools, including cordless drills.
As with every other type of technology, the science behind drilling has continued to advance through the years, from special drills for use in weightless environments by astronauts, to laser center finders for more accurate drill positioning.
Types of Metal Drills
A drill can be defined simply as a machine for creating a round hole in a workpiece by rotating a cutting tip to bore out material. The variety of drills, however, is anything but simplistic. The following are some common types found in woodworking and metalworking:
- Beam Drilling Line | A drill line is a large, enclosed, CNC structural drilling system that can perform a wide range of operations needed in steel fabrication, such as drilling, milling, countersinking, notching, tapping, and scribing. They are usually equipped with automatic tool changers.
- Drill Press | A drill press is a powered drill featuring a drill head attached on top of a column and an adjustable table that can be repositioned on the column depending on the size of the workpiece. While they often have tall columns mounted on a stand or to the floor, shorter versions called bench drills can be bolted to a workbench. Handles are turned on the drill head to move the spindle and chuck vertically in relation to the workpiece during the operation. They are popular due to their ease and accuracy.
- Gang Drill | A gang drill has several independently driven vertical spindles lined up in a row. It is used for drilling holes in a workpiece consecutively.
- Geared Head Drill | A geared head drill is a type of drill press that is designed for drilling larger holes than a belt driven machine can. Power is transmitted from the motor to the spindle through spur gearing inside the head.
- Magnetic Drill | Often called a “mag drill” for short, a magnetic drill is a portable drill press with a magnetic base that can be attached directly to a large or heavy workpiece that can’t easily be brought into a shop, such as a steel beam or the side of a ship. They are usually equipped with annular cutters that cut a groove at the outside of the hole, leaving a solid core or slug at the center.
- Mill Drill | A hybrid machine, a mill drill is a drill press that has a rigid table with X/Y coordinate movement like a mill to allow some light machining. The spindle of a mill drill is designed to accommodate the stresses of moving sideways while machining the workpiece.
- Portable Drill | A portable drill is easily moveable around a worksite and is usually a handheld pistol-grip drill that is either plugged in or cordless with battery power.
- Radial Arm Drill. A radial arm drill is a very large geared-head drill press with a head that can move out along an arm that extends (or radiates) from the center column of the machine. The arm itself can swivel around in a wide arc, allowing the head to drill in a wide range of positions across the face of a stationary workpiece, even several feet away from the center of the machine.
- Right-angle Drill | A right angle drill is a handheld drill with a low-profile drilling head set at a right angle to its body, allowing it to fit into places that are too tight or hard to reach with a traditional portable drill.
- Turret Drill | The head of a turret drill holds several different tools that can be rotated into place to be used as needed. It is useful for sequential work where different functions are performed progressively on the same workpiece.
In the Business of Selling Holes
Back before it merged with Black & Decker, The Stanley Works tool company hired a consultant to assist them in improving sales. He gave them a simple piece of advice that helped reshape their entire philosophy. He told them, “You are not in the business of selling drills. You are in the business of selling holes.” In other words, a machine is only as good as the result it produces.
It doesn’t matter what new metal piercing technologies are developed in the future, if drills continue to be manufactured that can still create a decent hole in metal for a reasonable price, the venerable metal drill will always be in demand, used by metalworkers of all types who need to center, counterbore, countersink, ream, spot face, tap, and—of course—drill.