If you have ever been around a tire shop you have seen and heard the sound of an air-driven impact driver knocking those lug nuts off a tire. The idea of a series of impacts instead of a steady twist is what makes a hammer drill or impact driver different than a power screwdriver or drill. Now these are available with cords or batteries. Don't expect to do work on engines or tires with them, though. These are made to take on smaller things like rusted nuts off of backyard grills or bicycles, for example. I had bought a Master Mechanic 1/2" hammer drill on closeout from my local True Value hardware store and it didn't work. Even though the sales receipt clearly said NO RETURN the True Value warranty allows returns for defective Master Mechanic power tools for two years. They didn't have a replacement available so they gave me full purchase credit for another tool. I chose the **Master Mechanic 18 Volt Cordless Impact Driver 565117.** **What it is** What I got in the cardboard box was the impact driver, a slim manual, and two hex drive bits, #1 and #2 long Phillips bits. As with other tools in the Master Mechanic cordless line, there was no [battery][1] or [charger][2] . The impact driver is compact and well balanced when the 18 volt battery has been slid into its rightful place at the bottom of the handle. Instead of some sort of adjustable chuck on the end, there is a single purpose chuck that accepts most quarter inch hex accessories like screwdriver bits, drill bits, or nut drivers. The bits have to have an indent in their hex shaft. Some don;t. Most do. You simply slide the outer ring out away from the drill body, slide the bit in fully and release. It locks the bit in place using that indent. It would have been better if the locking ring slid toward the tool body instead of away. It feels like you need three hands to get the bits in or out. I have added a few more bits to the two that came with the set. I have three slotted screwdriver bits, three square drive bits, and an adapter that allows me to use my set of 1/4" sockets. The trigger allows variable speeds based on how hard you press it. The no-load range is 0-3200 impacts per minute. With the motor torque of 203 inch-pounds this no-load speed reduces quickly under load. A white light is at the bottom front of the handle. It lights when the trigger is pushed and gives some light in dark places. The battery can rotate 360 degrees to allow a little more flexibility in tight places. Of course you lose the value of the light when it is rotated. The soft grips on the handle are nice and the balance is good. The brake stops the tool quickly when the trigger is released. There is no torque clutch but this is not a major flaw for this type of tool. **Some Uses So Far** I needed to replace a part on a smoker and the bolts were rusted. This baby knocked them loose easily. I have also used it to drive deck screws without first drilling a pilot hole. Works great there using square drive screws. I had a nut that had been cross-threaded onto its bolt. It took it off easily. This is not a tool you may need often and I probably wouldn't have it if I didn't want to get some value for the bad one purchased earlier. It is, however, one that is invaluable when you need it. [1]: http://www.viewpoints.com/Master-Mechanic-18-Volt-Battery-Pack-565067-review-1f22 [2]: http://www.viewpoints.com/Master-Mechanic-18-Volt-Smart-Battery-Charger-565004-review-fa731

epsgambler

Vancouver, WA