Cool Tools: Rotary Drills

Bosch 12V Flexclick 5-in-in-1 drill/driver
Published On
Sep 12, 2018

If there is a basic, must-have power tool, most electricians would agree it is a good drill/driver, and today that tool likely is a compact, powerful model powered by a lithium-ion battery.

The first portable electric drill was assembled in 1916 in the Baltimore shop of Duncan Black and Alonzo Decker. It had a universal electric motor, which could operate on either alternating current (AC) or direct current (DC) and a pistol-grip handle with a trigger control, but it was heavy and required two hands to operate.

Compare that to one of today’s lightweight lithium-ion 18-volt (V) models with multiple convenience features including LED lights to illuminate the work. Drill/drivers improved over time with the first cordless drill powered by a nickel-cadmium battery introduced in 1961. Milwaukee Tool introduced the breakthrough lithium-ion-powered tool in 2005, and more recent advances include tools with brushless motors, ergonomic and convenience features, and easy-to-install-and-change cutting accessories.

Most manufacturers claim their 18V lithium-ion tools have power equal to or exceeding corded drills. The 18V models remain most popular with professional users, but small 12V and 14V drills are increasingly popular. Lithium-ion batteries also have evolved, and toolmakers actively promote the benefits of their batteries.


Currently, 18V products make up a majority of the cordless power tools in the market, said Charlie Chiappetta, Bosch product manager. However, there is growing demand for 12V products, particularly from trade professionals such as electricians who are looking for powerful tools in a more compact design.

“Lithium-ion technology changed the game by offering the benefits of a consistent power draw, regardless of how much capacity remains in the battery,” Chiappetta said. “That means the first hole drilled and the last hole drilled have the same amount of power. In addition, these batteries have longer life than their predecessors. Electronically commutated brushless motors are more efficient and require less maintenance than previous-generation motors or brushed motors. In addition, drills equipped with LED lights on the tool mean it is not necessary for a work light in dark areas. A clutch on the chuck ring provides multiple settings, giving the user an additional layer of precision to ensure a fastener is tight or flush.”

The Bosch FlexiClick is an example of how handheld power tools have advanced from the basic three-jaw chuck.

“It is a compact 12V tool with four professional-grade attachments: a 3/8-inch keyless chuck, a locking bit holder, a right angle attachment, and an offset angle attachment,” he said. “These attachments offer easy adjustment for screw driving, drilling, right angle drilling/driving, and offset driving close to edges. The tool offers excellent flexibility for projects that range for electrical box installation to predrilling holes in hardwood.”

Hilti subcompact 12V drill driver with 10mm keyless chuck
Hilti subcompact 12V drill driver with 10mm keyless chuck


“We continue to expand our products to complete applications that are more demanding,” said Robert Chetelat, Hilti product manager, because the majority of professionals are using cordless tools more than corded products. “We have added active torque control to the SF 6H-A22 and SF 10W-A22 as standard features. This reduces the likelihood that the operator will twist a wrist or [be] pinched between the tool and an object.

“We see the expansion to cordless moving to smaller tools as well as larger. The replacement of hand tools is occurring with the introduction of our 12V tools, the SF 2H-A12, SFD 2-A12 and SID 2-A12. These are lighter weight and smaller in size. The power is perfect for applications where more control is needed. These tools are built to the quality of our 22V tools. We back these tools with our two-year, no-cost warranty,” he said.

Hilti designs many tools to have the same or even higher performance versus corded tools.

“We continue to improve here, but not all applications require such performance, so we increase the range of products to fit our users’ needs,” Chetelat said.

Makita brushless motor 18V XPHO7T LXT drill
Makita brushless motor 18V XPHO7T LXT drill


“In terms of power and speed, lithium-ion cordless drills have effectively replaced corded drills,” said Carlos Quintana, Makita senior product manager. “One instance where a corded drill might be the right tool for the job is taking on a continual and repetitive task near a power source, like drilling 1,000 holes in angle iron. But for most jobs, the power and speed of cordless drills, combined with higher amp-hour batteries, gives contractors the performance needed without the cord. With the charge times of our 18V LXT batteries, users can recharge in less time than an average lunch hour.

“The market has shown a clear preference for the power, speed, run-time and ergonomics of 18V. However, 12V and 14V is preferred by some for the compact size. Professional users benefit from lithium-ion batteries for three reasons. First, the weight of an 18V lithium-ion battery is approximately one-half the weight of an 18V [nickel-cadmium] battery. Second, lithium-ion batteries have more life cycles than older battery technology. And third, lithium-ion batteries don’t have the draw-down of old technology. Charge a battery on Friday and Monday morning the lithium-ion battery still is ready to work,” he said.

Efficient brushless motors do not have carbon brushes around the armature, so they are smaller than brushed motors. This enabled more compact and efficient tools to be built around brushless motors.

“Makita developed brushless motors in 2003 for precision fastening applications,” Quintana said. “In 2009, the first three-speed brushless motor impact driver was introduced. Today we have purpose-built brushless motors for use in a full range of tools, from drills and compact impact drivers, rotary hammers and more.”

Combining higher amp-hour batteries with efficient brushless motors proves superior cordless performance that can last all day. In addition to lithium-ion and brushless motors, Quintana cited slide-in batteries as a big step forward in ergonomics, especially for fastening tools such as drills and impact drivers. Without a battery stem extending into the handle of the tool, the grip can be designed around the human hand, not the stem of the battery.

“We also created 18V X2 [36V] tools powered by two 18V batteries,” he said. “Users benefit with 36V power and run time, but without having to manage separate battery platforms or invest in heavy slow-charging batteries with limited compatibility and poor ergonomics. Users simply load two 18V batteries, the same batteries that power 18 LXT cordless products.”

Milwaukee M12 RedLithium drill
Milwaukee M12 RedLithium drill

Milwaukee Tool

Handheld electric drills are getting smaller and lighter and, at the same time, out-performing their corded counterparts, said Cole Conrad, director of product marketing, Milwaukee Tool.

“So much has happened since Milwaukee Tool introduced lithium-ion technology to power tools,” he said. “Significant leaps forward in motors and tool electronics, coupled with advancements in lithium-ion technologies, have pushed the industry to a point few would have considered possible 10 years ago.”

When it comes to cordless power tools, Conrad said many users believe that power is measured in battery voltage.

“However, as new technologies have been introduced and evolved, this is far from the truth in today’s market,” he said. “Just because a voltage number may be higher doesn’t mean it has more power. Rather, professionals should look at the solutions the tool provides for the applications they commonly encounter. Many power tool companies cite higher voltage batteries, but have ineffective motors or electronics. By tying brushless motors to the world’s most capable electronics packages and most advanced lithium-ion batteries, users can truly push the boundaries of cordless tool performance and experience the enhanced productivity it provides.”

The complex inner working of lithium-ion batteries, motor technologies and electronics have contributed to the dramatic changes in the range of drills available today.

“Our M12 [12V] Fuel products of today outperform the leading 18V drills of 2007–2008,” Conrad said. “And, 18V drills today are now completing applications that only high powered (12A and 15A) corded drills completed 10 years ago. Not only are they powerful, but they are extremely compact.”

Through advances in motor and electronics design, Conrad said new ways are being found to achieve much more from an 18V system than ever thought possible. New brushless motors for drills pack more overall power in a smaller footprint. Sizes of sophisticated electronics are being reduced to save space and increase thermal capacity and communication between the tool, motor and battery. Both drill and impact mechanisms have been optimized to deliver more raw power in the smallest package possible.

“In addition, new 18V, ½-inch drill/driver and hammer/drill have chucks with black oxide jaws and an updated sleeve knurl pattern for superior bit retention,” Conrad said.

A self-tapping screw mode shuts the tool off once a screw is seated to reduce overdriving, breaking and stripping out screws.

Also, smart technology for tools has arrived. Conrad said Milwaukee drills and many other products are compatible with Milwaukee’s One-Key technology.

“One-Key provides a new level of control and access to information that changes the way work gets done,” he said. “Combining a free-to-use inventory program with the smart tools, One-Key users can customize their drill performance, track their drill’s location, secure and lock out their drill if its lost, and keep an inventory of their drill and any other tools. This can all be done via the One-Key app on mobile phones.”

About the Author

Jeff Griffin

Freelance Writer

Jeff Griffin, a construction and tools writer from Oklahoma City, can be reached at

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