2022-05-14 20:37:03 By : Ms. Joan zhong

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And less guesswork makes for faster, better, safer tightening.

The Takeaway: The Gearwrench 89620 torque screwdriver’s calling card is its ease of use, especially when it comes to getting bolts and screws to just the right level of tightness. See, it has a drive mechanism that disengages when it reaches a specified level of torque (which you set). You’ll hear a distinct click as the handle disconnects from the drive bit. For reliably tightening a variety of electrical terminal screws and small bolts with heads up to 1⁄2 inch, there are few tools better.

If you peel back the National Electrical Code, auto service manuals, and repair manuals for appliances, office machines, and many other mechanical devices, you’ll find torque specifications. These provide specific tightening measurements for electrical terminal screws and various bolts and machine screws that hold parts together. The intent is to increase the reliability and safety of mechanical fasteners. Screws and bolts can loosen due to both under-tightening and over-tightening. In electrical connections, a loose screw can lead to an electrical lead coming loose and perhaps sparking a fire. Over-tightening is just as dangerous, because it can cause an electrical terminal screw to fail suddenly and unpredictably, with the same results. In purely mechanical applications, a loose part can lead to a malfunction, possibly even a dangerous one as parts come loose and go flying. Without a torque-sensing tool of some kind, you’re left to guess how tight to make a screw or bolt. And numerous tests have established that people have no idea how much force they’re applying when tightening fasteners. They need a tool that tells them.

This GearWrench screwdriver is that tool. The kit consists of a torque screwdriver that senses 10 to 50 inch-pounds of torque, and it comes with a lab certificate testifying to its precision of plus or minus 6 percent. Its center shaft is marked in 10-inch-pound increments beginning at 10 and ending at 50. At the base of the shaft is a rotating collar in 1-inch-pound increments. Press down on the tool’s lock ring and turn the collar until you get the inch-pound setting that you need lined up with the correct 10-inch-pound increment, such as 25 inch-pounds (the 20-inch-pound line on the shaft aligned with the 5-inch-pound setting on the collar). Tighten the screw, and when the specified tightening torque reaches 25 inch-pounds, the tool’s mechanism disengages and the screwdriver stops tightening.

But that’s not the tool’s only user-friendly feature. In the base of the screwdriver handle is a recess that fits the drive of a 1⁄4-inch ratchet wrench. If you have a long row of screws or bolts to fasten, this is a particularly nice feature in that the wrench’s handle not only provides tightening power but you also benefit from the tool’s ratchet action.

The screwdriver itself is beefy and built for rugged use. Likewise, its kit is also robust. The screwdriver is protected by a blow-molded case that snaps securely shut. It houses 19 commonly used screwdriver bits—both 3-inch and 6-inch lengths in slotted, Phillips, hex, and two sizes of square drive (R1 and R2), and nut drivers from 3⁄16 inch to 1⁄2 inch. Although there are no Torx bits here, the screwdriver will take any standard 1⁄4-inch hex shank drive bit.

Combine all these features into one kit, and there’s no excuse for an improperly tightened machine screw or small bolt.