116 ELECTRICALCONTRACTOR | SEP. 17 | WWW.ECMAG.COM
surface finish, and insufficient life overall. All of these challenges
add up to increased downtime and reduced efficiency.”
It wasn’t many years ago that a corded tool would have been
an absolute necessity for many of an electrician’s drilling and
cutting jobs. Today’s cordless tools offer more power and are
more capable of driving higher torque for applications com-
monly encountered on electrical jobs.
“A key change in cutting accessories is the higher usage of
carbide and cobalt materials in many blades and bits,” said Rod
Bentley, product manager for knockouts and power-tool accessories, Greenlee, Rockford, Ill. “Not only is it important to use
the correct cutting accessory for material being cut, but the tool
must be operated correctly. For example, drilling into stainless
steel requires not only a special bit, but the power tool must also
be used at low speed, with the proper amount of force. Drilling
stainless steel at high speed will burn up the bit or blade being
used and could harden the material, which makes penetration
“Drilling into wood that may contain nails requires using a
bit that is specially hardened to stand up to nails. The hammer
attachment that accompanies many tools is an important accessory. In high-torque applications, it is very difficult to handle
the drill with one hand. Not using the hammer attachment in
high-torque applications can result in injury.
“Impact drills are great driving tools, but there are definite
limitations when it comes to drilling. Many users make the
assumption that any accessory with a ¼-inch, quick-connect
shank must have been designed for use with an impact drill.
The larger the diameter of the bit, the more likely it is that the
shank will not survive,” Bentley said.
Most of the special coatings Greenlee has tested did little to
improve cutting performance or justify the added cost.
Greenlee offers a
selection of step bits.
Drill bits, saw blades and other cutting
accessories are used for multiple
purposes, but knockout tools are
specifically designed for punching clean,
conduit-size holes in steel electrical
panels, boxes and other surfaces,
including aluminum and fiberglass.
While the knockout tool’s basic
purpose hasn’t changed, battery-powered knockout tools bring
significant advances to improve
the hole-punching process. In May,
Milwaukee Tool introduced Exact Rapid
Reset draw studs for use with its lithium-ion powered M18 Force Logic knockout
system. Available in 10- and 6-ton
models, the Force Logic system speeds
up the knockout process by enabling
punches and dies to be quickly aligned
on the work surface without the tool’s
weight. The user then snaps the tool
onto the punch-and-die assembly and
pulls the trigger to punch the hole.
Rapid Reset draw studs simplify
the process of punching repetitive
holes by removing the tedious step
of unthreading the punch from the
draw stud, said Paige Bovard, group
product manager, Milwaukee Tool. A
one-quarter turn releases the ball pull,
the slug is dumped, and set up for the
next hole requires only another quarter-
inch turn to lock the ball pull back on,
eliminating the need to thread and
unthread punches between holes.
Greenlee’s battery-hydraulic 11-ton
IntelliPunch tool introduced in 2016
features patent-pending auto-retract
technology that senses pressure, detects
punch completion and automatically
retracts the ram, preventing damage
to punch parts. It has a maximum cycle
time of eight seconds.
“The auto-retract feature adds
actual intelligence to the tool,” said Rob
Bentley, product manager, Greenlee.
“IntelliPunch ensures the tool has
released from the material, stops the
tool before over-punching can occur,
and eliminates the need to manually
retract the tool after
The IntelliPunch tool
delivers 11 tons of force,
capable of punching up
to 4-inch conduit-sized
holes in 10-gauge mild
or stainless steel and
6-inch conduit-sized holes
in 14-gauge mild steel. A
patent-pending swivel head
rotates 360 degrees, enabling
the user to punch at any angle
and in tight spaces. —J.G.
Continued from page 114
Reset draw stud
Continued on page 118 ➜