Electricians mainly use reciprocating saws, band saws and circular saws with metal cutting blades. Cutting accessories play a critical role in saw efficiency (see sidebar).
For years, hand power saws were corded. Battery-powered models were introduced and added portability, but they came with less power and called for the frequent need to change and recharge batteries.
Then Milwaukee Tool introduced the first line of tools for professionals powered by a lithium-ion battery.
Electrical Contractor’s July 2005 issue quoted the late Dennis Rhees, a national product specialist at Graybar, saying he believed the emergence of battery-powered hand tools was the most significant technological development in his company’s then 136 years in business.
He called the introduction of lithium-ion tools “a cordless tool breakthrough.”
Other tool-makers also jumped into the lithium-ion-powered tool market.
In addition to being lighter in weight, more powerful for their size and providing longer run times, lithium-ion saws and other tools today are being promoted as equal to or exceeding productivity of corded tools with the same power rating.
“We firmly believe our cordless systems eliminate the need for AC,” said Andrew Plowman, Milwaukee Tool vice president of product marketing. “We have been delivering corded power in cordless tools since 2012, and we are very close to closing the gap on the remaining heavy-demand situations where a cord is truly needed. We now are able to design compact saws that provide not only great power but [are] also very maneuverable and can withstand the harsh conditions out on the job site.”
Plowman summarizes primary uses of the basic cordless saws used by electricians:
Reciprocating saws make easier cuts in tight spaces between other materials, and they are an option for cutting EMT, threaded rod, nonmetallic conduit, metal studs and Unistrut when installing electrical systems.
Metal cutting circular saws are good for a wide range of demanding cutting applications, including sheet metal and plate steel, and the capability of making cold cuts, unlike grinders and band saws, means the user can work with the material immediately after a cut is made.
Compact cordless band saws have become increasingly popular due to their maneuverability and ability to be used in tighter spaces and overhead work. They are ideal for cutting EMT, threaded rod, conduit and Unistrut, and they also are a good choice for making cuts overhead, flush to a wall or in a vice. The band saw is especially popular because it makes clean and consistent cuts with user ease. The downward momentum of the tool does almost all of the work.
Plowman said Milwaukee has taken the compact band saw a step forward with its 12 volt (V) subcontact band saw that can be used with one hand.
“Advancements in technology also have allowed tools to become ‘smarter,’” he said. “An 18V saw with One Key app allows users to adjust the speed of the tool for smoother cut starts, engage an automatic cut brake and optimize longer blade life.”
Hilti Product Manager Michael Lowe said cordless saws have almost entirely replaced the demand for corded equipment.
“In extremely demanding applications, cords may still be preferable. Because of the advancements in prolonged run-time, due to improved heat dissipation and increased energy density, cordless tools will often cut as fast or faster than corded models,” he said.
What do buyers look for in cordless saws?
Once the requirement for cutting speed has been met, Lowe said, users want a battery charge to last for the next job.
“When this is achieved, most saw users recognize it often is far more productive to make the occasional trip to a battery charger to exchange batteries rather than dragging a cord around behind a tool,” Lowe said.
Ease of use is a consideration in purchasing decisions.
“Products continue to become more compact and lighter in weight,” he said. “We employ ergonomics experts and get feedback directly from professional customers. Durability also is high on buyers’ lists of requirements.”
Meanwhile, batteries keep improving.
“Thanks to massive investments in lithium-ion technology, the energy density in batteries has improved,” Lowe said. “More energy capacity can fit in battery cells now than two years ago, and the performance of cordless tools tends to improve as batteries improve, although it is not the only influencing factor. Brushless motors also offer improved performance and tend to last longer before requiring maintenance.
“In general, the most common saw application for electricians is cutting to length. Reciprocating saws and band saws also are used for light demolition when work needs to be corrected,” Lowe said. “Metal circular saws are cold-cut saws and produce spark-free cutting, and the material being cut doesn’t heat up, so it can be handled right away.”
Compact cordless band saws, Lowe said, are becoming more popular because they cut accurately and tend to offer low heat and sparks when cutting ferrous and nonferrous metal. These tools have become increasingly compact and lightweight.
DeWalt Product Manager Daniel HeineyGonzalez said reciprocating saws and portable band saws are two of the main saws electricians use, and the evolution of the battery technology has provided capabilities to cordless saws and other tools that weren’t achievable a few years ago.
“Band saws are the saws most used by electricians as they can be used to cut conduit, threaded rod, strut or other materials,” he said. “Reciprocating saws can do many of the same applications, but they do not provide as clean a cut because they do not have the blade tracking of a band saw.
“Traditional portable band saws have the ability to make 4-inch and greater cuts while most electricians will make cuts of 2 inches and less, which makes the compact band saws ideal. Having the smaller opening for the material, and being a lighter weight tool, means it offers more control to get the needed clean cut. And for band saws specifically, the most important new feature in the past two years is the dual trigger,” he said.
Metabo HPT is now the name of the Hitachi power tool line. Trey Brandon, Metabo product manager, said any opportunity to eliminate a cord on a job site should be taken.
“With today’s battery technology incorporated into products, such as cordless reciprocating and cordless circular saws, companies are pushing the boundaries of power, run time and performance,” he said. “Battery technology has improved to the point where users can justify leaving the corded tools at home. Brushless motors are becoming increasingly common across all price points of tools, which reduces the need for maintenance and tedious upkeep. Size and weight of cordless tools have decreased where they’ve needed to and are getting continuously safer and more comfortable to use.”
A “hybrid” tool platform allows a series of tools to be run on the same lithium-ion batteries or with a universal AC adaptor.
The most attractive features of a cordless band saw, Brandon believes, are cut capacity and cuts per charge. Band saws are preferred in certain applications that call for clean cuts to eliminate the extra step of deburring after the cut. Cut capacity allows the band saw to be used for more applications, and the run time or cuts per charge brings more freedom and portability. More battery life means less battery charging and replacing, resulting in more convenience for the user.
A saw’s cutting efficiency is directly affected by cutting accessories. No matter how good the tool, if saw blades are poor quality, damaged, worn or wrong for the material being cut, productivity and sometimes safety are diminished.
Andrew Plowman, Milwaukee Tool vice president of product marketing, shares his observations about saw blades:
Several advancements have been made in optimizing tooth geometries and processes across bimetal blades, Plowman said, and most recently there has been a major push in developing reciprocal blades with carbide teeth.
“When it comes to extreme cutting applications and versatility in a wide range of materials, carbide technology can deliver longer life,” he said. “However, not all carbide blades are equal—some may have carbide grade that is soft. This leads to good durability, but this soft carbide will round off and fail prematurely. Others are too hard, resulting in teeth that chip and fracture early in the blade life. This has a major effect on productivity.
“Just having carbide teeth doesn’t guarantee the best performance. The blade must also have the correct tooth design. Optimizing tooth design on carbide blades delivers the longest life and best durability.”
Plowman cited research on band saw blade usage that found the biggest user frustration was changing the blade, and, to avoid this task, some users would knowingly use the wrong blade for the material to be cut.
“To address this frustration, Milwaukee released Extreme Metal Band Saw Blades that have variable teeth per inch so that there is no need to switch blades when cutting different materials. In addition, these blades cut two times faster in thin metals and achieve three times longer life in stainless steel,” Plowman said.