Published In March 2001
Cordless tools can successfully supplant their corded brethren in many scenarios, including situations that would otherwise call for running out extension cords for short tasks in many locations throughout a facility or when working in heavily occupied facilities. While not suitable for continuous (therefore battery-draining) jobs, cordless tools can often save enough effort in set-up time that they could be well worth having on many jobs. Along with battery longevity and effective portability, look for safety features, ease of use, overall feel of the tool, switch location and action, and desired handle type. While some manufacturers offer the same tool with a choice of handle design—typically pistol grip or T-grip—others offer just one. A pistol grip is the traditional-looking handle at the back of the tool. With it, the operator generally can easily use more force to push the tool into the work surface than is possible with a T-grip because the trigger hand is in, or close to being in, direct line with the bit, so the push is directly into the work. A T-grip, located at, or near, the center of the tool and running vertically, gives the operator more control by affording more leverage. The T configuration also helps control torque whip. Some tools, including drill drivers, are particularly well-suited for T-handles, whereas a pistol grip might work better on small cordless drills used on lightweight work. Some users prefer T-handle tools because of the balance in the hand. Users who are making repetitive fastenings and drilling holes repetitively prefer pistol-grip tools. Ultimately, handle choice is dependent on buyer preference for a combination of feel, styling, and functionality. There is often a compromise when you take a cordless tool in hand—some sacrifice of run time, not to mention altered weight distribution because of the location of the battery—in return for portability. You might notice other differences, as well, during performance. A potential downside to cordless recip saws, for example, is that, unlike some of their corded cousins with blades that can move in orbital paths that clear the blade out of the material and clean the teeth before plunging back into it, the blade—to save battery power—moves less aggressively with a straight motion. Given the opportunity, electrical workers might benefit from such cordless tools as circular and recip saws (useful for plunge cuts, notching into framing studs, oriented strand board, and plywood, as well as other materials), impact drivers, and drill drivers, all of which can have fairly potent capabilities. The Hitachi C6DC 61/2-inch 18-volt circular saw cuts to a maximum depth of 21/4 inches at 90 degrees and 19/16 inches at 45 degrees, and a bevel capacity of 45 degrees. Featuring an electric brake that stops the action immediately when the trigger is released, the tool, which could be handy for cutting a sheet of plywood for mounting a panel, is equipped with a light that illuminates the cutting line when the trigger switch is pressed. The tool can also be used to cut conduit and other nonferrous metals at the actual work site as opposed to at a central cutting station on the job, Hitachi noted. While still less widely recognized as an everyday battery-operated option than circular saws, the cordless impact driver is an increasingly popular alternative to a cordless standard driver drill, at least because they can deliver more torque with a faster speed. Furthermore, the fast-pulse action of the impact driver prevents the operator from feeling the torque in the wrist. Available in various voltages, they offer diverse combinations of power, speed, and control. Plus, it is often possible to add a chuck and use that with regular 1/4-inch drill bits and step bits. The impact driver can yield higher RPM and more torque in a smaller-diameter tool in comparison with a drill driver, at very little added initial cost, noted Ken Hefley, vice president of marketing at Makita. An impact driver has the speed to drive self-tapping sheet metal screws. When it reaches the preset torque, it moves into an impact mode that delivers pulses of intensive torque to set or remove tough screws or nuts from the holding material without requiring application of undue pressure and without camming itself out of the screw slot once the screw becomes difficult to drive (as a regular screw gun might). According to Hefley, a 9.6-volt impact wrench/driver produces more torque than an 18- or 24-volt drill/driver unit and, “would be excellent for removing older rusting nuts and screws without snapping your wrist from the torque.” Makita has several models of impact drivers, including a compact, lightweight 9.6-volt unit (6908DWAE) that produces 700 inch pounds of torque with 2,200 RPM maximum speed, a 12-volt model (6914DWBE) that produces 870 inch pounds of torque with 2,200 RPM maximum speed, an 18-volt unit offering 404 inch pounds of torque at 1,400 RPM maximum speed, and a 24-volt model (BTD200SH, available either with a 1/2-inch square drive or 1/4-inch hex shank) that delivers 1,774 inch pounds of torque at up to 2,100 RPM. Hilti 9.6-volt and 12-volt cordless drill/drivers, SF 100-A and SF 120-A, both feature one-hand oper-able keyless chucks with single sleeve and spindle lock. Offering two-speed gear settings, the units take either a 3 amp hour NiMH battery or a 2 amp hour nickel cadmium battery. Capable of drilling into various materials including wood and steel, the drill/drivers, which weigh in at less than 4 pounds and 5 pounds respectively, are well-suited for repetitively driving screws or installing fixtures throughout a facility. The tool’s planetary gear reduction system uses metal gears rather than nylon ones, for greater withstanding of the “abuse” of shifting on the fly, rather than after the gears stop rotating, also providing greater durability in high-torque applications, the manufacturer said. The drill drivers have 20-position torque adjustable clutch settings that Product Manager Kevin Kolbeck said, “help prevent rotation of the tool as long as lateral pressure is maintained.” An electronic sensor in the switch varies the torque while maintaining even speed to help prevent cam out and overdriving or stripping out fasteners, as well. Sometimes, manufacturers group popular, oft-used cordless tools as a kit or package, typically in a carrying case with charger, battery, bits, and blades. Bosch 3960CRK 24-volt (2.0 AMP HR) three-tool combo pack assembles the Model 1645 reciprocating saw with a quick-change blade system and a three-position pivoting shoe that optimizes the length of the exposed blade; the Model 3960 1/2-inch drill/driver with dual zero to 400 and zero to 1300 rpm ranges and 1/2-inch quick-release, single-sleeve chuck (allowing one-handed bit changes) with automatic shaft lock; and the Model 1660 61/2-inch circular saw with 3600 rpm, a 21/8-inch depth of cut, and bevel adjustment to 50 degrees. The recip saw offers long-stroke (for more aggressive cuts) and short-stroke (for more precise cuts) settings. Both strokes cut at a rate of zero to 2,300 strokes per minute (SPM). The short stroke is well-suited for metal cutting and plunge cutting, providing less opportunity for kickback and tear and yielding less vibration (similar to a hacksaw when cutting conduit) and keeping the blade as still as possible, while the long stroke is well suited to cutting wood, optimizing the number of teeth used, said Kurt Honaker, industrial specialist at Bosch. For user safety, the unit features an electric brake for instant stop upon trigger release. DeWalt has an 18-volt combo kit (DW4PAK-2), with a hammerdrill/drill/driver (DW997), a recip saw (DW938), a 61/2-inch circular saw (DW939) and a xenon-bulb floodlight with a flexible neck for hands-free lighting. The DW997’s hammerdrill chuck features an automatic spindle lock that accepts a single-sleeve chuck (for one-handed bit changes) and, because it is easier to grip with a hand, allows the user to close the chuck 50 percent tighter, the company pointed out. The drill/driver has carbide-tipped jaws and ratcheting action, which, DeWalt noted, help protect against slippage caused by the extreme bit vibration during hammer-drill applications. The tools all sport impact-resistant polycarbonate/ABS plastic housing and anti-slip, vibration-absorbing comfort grips. The recip saw, sporting an electric brake, has a lever-action keyless blade clamp and a 7/8-inch stroke length. The circular saw, with left-side blade for maximum visibility, cuts 2x4 in a single pass: 90 and 45 degrees and runs at 3,700 rpm. Milwaukee 18-volt Power-Plus Contractor Cordless Combination Kit (model 6515-28) includes a Sawzall (model 6515-28) with Quik-Lok All-Metal keyless blade clamp system that accepts standard 1/2-inch shank Sawzall blades and a 1/2-inch T-Handle Hammer-Drill (model 0524-20) with variable-speed switch, 20-position clutch, two-speed ranges, and an All-Metal Grip-Lok keyless chuck that manually “locks” the bit or driver into place. With trigger speed control, zero to 2,200 SPM, that allows the user to adjust the blade speed to accommodate the work material, the Sawzall uses a 1-inch blade stroke for fast cuts and offers pivot shoe adjustment for maximum support against the work surface, efficient blade use, and greater depth-of-cut control. Delivering up to 20,800 blows per minute (BPM) and capable of developing 400 inch pounds of torque, the Hammer-Drill has a reversible battery feature that allows the user to slide the battery on from two different directions. This affords better weight distribution when working overhead or enabling the user to more easily angle the tool into tight spaces. The FELDMANS provide Web content for companies and write for magazines, trade associations, building product manufacturers, and other companies on a broad range of topics. They can be reached at firstname.lastname@example.org or (914) 238-6272.