Power drills are among the most basic power hand tools electricians use, and the application determines which type of drill is best suited for a job.

For tool buyers in all trades, cordless models have become the product of choice, and that certainly applies to drills. Although cordless tools were growing in popularity before the introduction of the first lithium-ion powered tools in 2005, lithium-ion platforms have revolutionized the cordless tool market.

Even so, many nickel cadmium (NiCad) drills and power tools remain in use, and NiCad products still are available. And, of course, there are applications for which corded drills and cutting tools are better choices than cordless models.

Most popular with professionals are 18-volt (V) drill models, but becoming increasingly popular are 12V “pocket” drills, which pack surprising power for their size and are easy to carry and use.

Lithium-ion revolution
When an electrician purchases a cordless drill today, whether an 18V tool—still the standard for professional tool users—or a compact 12V model, the chances are it will be powered by a lithium-ion battery. In fact, lithium-ion battery technology is a primary reason many types of tools are available in cordless versions.

“No technology has made an impact to the power tool industry like lithium-ion batteries,” said Shane Moll, senior vice president of marketing and general manager, tools, for Milwaukee Electric Tool Corp., the company that introduced lithium-ion products to the professional tool market.

Lithium-ion tools have taken a tremendous portion of the drill market, Moll said.

“When Milwaukee talks to electricians on the job site, we don’t run into many users asking for a cordless drill that is heavier, larger and provides less run time,” he said. “Nickel cadmium simply fails to deliver what today’s lithium-ion can provide. Lithium-ion technology’s continuing evolution makes nickel cadmium obsolete for the professional user. With continued advancements, tools are getting smaller, more powerful and, overall, delivering greater productivity to the user.”

The other big change in today’s cordless drill, Moll said, is the use of electronics.

“Onboard electronics make possible features, such as electronic clutches, overload protection and temperature control, and provide users with smaller, more ergonomic, better performing tools,” he said. “We don’t want the user to have to think about what is going on inside the tool but to have the confidence when the trigger is pulled, it will get the job done.”

Moll said that, overall, the cordless hammer drill/driver is the most common tool used by electricians due to the versatility of drilling and fastening in various materials encountered on commercial, residential and service jobs. When looking at pure fastening applications the cordless impact driver has grown in popularity with electricians due to the compact size, light weight and superior fastening performance, he said.

In addition, rotary hammers are also widely used for anchoring and drilling holes in concrete.

Edwin Bender, cordless group product manager, Robert Bosch Tool Corp., said the benefits of lithium-ion technology are clear as soon as a lithium-ion drill is picked up and used.

“They are more powerful and compact,” he said. “The 18V hammer drill remains the most popular drill model with electricians. However, many electricians, especially those that spend most of the time on fixtures or service call applications, do not require 18 volts of power and prefer a compact, lightweight, reliable drill that will hold a charge well even during downtime. Lithium-iontechnology has made it easy for tradesman to see that they don’t need a bulky, heavy-duty tool to accomplish 80 percent of their tasks—12V tools can do that. The lower voltages have more than enough power to help them efficiently complete a job with less fatigue. This has made them the fastest growing category of cordless tools.”

Bender said another benefit of lithium--ion technology is that a user can choose lighter weight or longer run time within the same voltage platform.

“Flexible power systems allow the user to choose between 18V slim packs (lighter weight) and 18V fat packs (longer run times). With NiCad, in order to reduce weight, you had to switch to a different voltage platform. For those who like to have a wider assortment of tools, the 18V platform is still the largest and most versatile,” he said.

In addition to drill/drivers, Bender said electricians use hammer drill/drivers, impact drivers and, to a lesser extent, rotary hammers.

Christine Potter, DeWalt director of cordless tools, said 18V drills and tools remain the standard for electricians, but 12V tools are popular because of their ability to complete the range of applications electricians need.


Types of Drills
With the variety of drills available today, there may be confusion about terminology of specific types of drills and their capabilities.

Drills commonly used by electricians includes the drill driver, hammer drill, and rotary hammer. The brief descriptions of each product that follows includes information provided by Milwaukee Electric Tool Corp.

Drill/driver—a motor rotates the drill bit to drill holes in wood, plastic or metal; it is not suited for drilling in concrete and one of the following options is recommended instead.

Hammer drill—the most popular drill with electricians is two drills in one. Similar to a drill driver but with a hammer function created by two ratcheting plates that click in and out against each other, creating a percussion force, a hammer drill is ideal for drilling in soft concrete and cinder block. Users can quickly switch off conventional drilling to work in harder surfaces.

Rotary HammerS are needed for heavy-duty concrete applications. Working like a hammer and a chisel, its impacting force is created by a piston that pushes and an anvil that directly strikes the back of the bit as it rotates, allowing the bit to become a powerful chisel to quickly break concrete.

Hammer drills delivery a high number of blows per minute (BPM) with relatively low impact, while rotary hammers use lower BPM with a much higher energy impact.—J.G.


“Our 18V hammer drill,” Potter said, “is the most popular DeWalt cordless drill for electricians, providing enough power and run time to complete the range of applications performed by electricians. From small screws up to hole saws, the hammer drill provides the versatility of having a drill, driver with clutch, and hammer. However 12V products are emerging as a complement to 18V. The 12V line is ideal for driving small screws and fits nicely in a tool belt, but 18V is still needed for drilling with a hole saw.”

Cordless drills continue to provide more power and run time while the size and weight is decreasing, and light-emitting diodes are now very common on cordless drills, Potter said. She added that residential electricians often purchase cordless combo kits including an impact driver, reciprocating saw and circular saw; commercial electricians will also have a rotary hammer and impact hammer as primary tools.
Wayne Hart, communications manager, Makita USA, categorizes compact 12V lithium-ion drills and tools as a useful extension in the cordless category and these products will find niche audiences in finish work or for do-it-yourselfers and others. But for professionals, it’s all about 18V lithium-ion.

“However, the commercial electrician and other professional users will pick up an 18V tool any day of the week over a 12V tool—especially since the tools are similar in size, yet the 18V tool has more power and a faster charge time than a 12V tool,” Hart said.

NiCad tools
Thousands of NiCad-powered tools, including drills, remain in use on residential and commercial electrical and datacom jobs, and DeWalt’s Potter said they remain the largest segment of the cordless market because of their proven job-site durability and value. The first lithium-ion drills and tools were priced significantly higher than traditional NiCad products, but as more companies introduced products to the market and competition increased, cost has become less a factor, and lithium-ion is the fastest growing segment in the cordless market.

Corded drills
Electricians still may have a need for corded drills in applications such as drilling a large number of large diameter through-holes in concrete where cordless is simply not a productive option, said Milwaukee’s Moll. But as seen with the growth of lithium-ion, as cordless technology continues to improve, the dependence on plugging in a corded drill continues to wane. Drilling larger diameter holes through concrete and masonry, as well as situations where there is a very large number of holes to be drilled, are applications suited for corded products, said Bosch’s Bender. The lower cost of corded drills also can be a factor, Potter said.


GRIFFIN, a construction and tools writer from Oklahoma City, can be reached at up-front@cox.net.