Masonry Magazine August 2006 Page. 29
Superman returned to the theaters this summer and
cordless drills, hammer-drills and rotary hammers are
returning to the mason's toolbox. What, did you say? Neither was ever gone?
Superman might have been taking just a leave of absence, but cordless drills were seen even less.
Cordless was tried and found lacking at the beginning, a decade ago, due to low power, short battery life and limited usability. "The tools, when they first came out, started with 9.6 and 12 volts," recalled Edwin Bender, group product manager for cordless power tools at Bosch Power Tools, Mount Prospect, "But their development didn't stop there, it kept moving up to 14 and 18 volts because when you go into large diameters and into masonry, you need 18-volt power. That is one thing that has changed over the years that has now become the norm, and so the tools are now more reasonable to use. Masons need that level of power to feel like their getting enough productivity out of their tools. Now, lithium ion is taking it to the next level because you're able to double your run time, have twice as much power, and do more tasks than you could before."
Agreeing is Terry Tuerk, product manager for Metabo Corporation USA, Sellersville, Penn. "Today's cordless tools pack is typically 18 to 36 volts. At that power level, the tools are nearly as strong as corded tools, without the weight, the cord or the extension cord, making them most favored in overhead applications, working from a ladder or scaffold, or where an electrical mains source is not available. However, corded tools particularly rotary hammers are still the tools of choice when drilling multiple holes, large diameter holes or where the hole being drilled is at the feet.
"Advances in battery chemistry have made cordless tools more practical," he continued. "The first advance was the increase in the amp hour ratings of batteries, first in Nickel Cadmium (NiCad), then in Nickel metal hydride (NiMH) in the past four to five years. The amp hour rating of a battery pack can be equated to the size of the gasoline tank; the higher the number, the longer the battery can provide energy for the application. Today's NiCad and NiMH batteries carry 2.4, 3.0 and higher amp hours, giving the tool the energy reserve needed to make the cordless tool practical."
Cordless power tools for professionals, regardless of industry, are usually made with harsh environments in mind. Peter Hagicostas, director of quality assurance and new product development at Great Neck Saw Manufacturing, Mineola, N.Y., puts it in perspective, saying, "The models designed for the contractor and professional exhibit various attributes to handle the rugged and continuous uses they will face from day to day. They also have developed various voltages to accommodate a variety of tasks. This level of quality is ideal for all trades, including masonry. Certain types, such as hammer drills, are designed with them in mind. The reason is quite simple:
They must be affordable, reliable, as well as durable and tested for 'fitness for use. They are designed to meet the daily challenges of handling, dust, moisture, weather, consistent use and more. Power tools in general are treated quite harsh on the job site; therefore, they must be designed and built to handle this environment."
Taking the discussion a little further is Robert Chetelat, product manager for cordless drills/drivers at Hilti North America, Tulsa, Okla. "Cordless hammer drills are well suited for masonry applications because they operate on a cam-action hammer mechanism. This has less impact force per blow, but high frequency of blows per minutes. Cam-action tools help reduce cracking and spalling when drilling into stone or masonry.
"Electro-pneumatic rotary hammer drills operate with the hammer mechanism riding on a cushion of air, are designed to
The Voice of the Mason Contractor
August 2006
Masonry 27