What's an amp worth?

After having training from a few of the major power tool companies in the world, I've learned a few dirty little secrets of the power tool industry. Today, for Christmas, I'll share the big one!

You know that amp rating that so many consumers use to determine how much {insert manly growl} power a tool has? It really means very little. The rating process is kind of silly. The testing labs get a tool from a manufacturer and are told "We would like to be rated for 12.0 amps". The testing lab then puts heat sensors in certain areas of the tool, and then apply the requested current to the tool... as long as the sensors do not get above a set temperature in a set amount of time, then the lab says "Hey this is a 12.0 amp tool!"

Sure, the tool can operate at 12 peak amps, but is it using that power effectively? Is it transferring the energy it is producing to the work piece or is it simply shaking the tool out of your hands? I have seen tools that have a lower amp rating out-perform high amp tools on a regular basis.

In addition to the question about efficiency, the next one you should ask is how many amps is your circuit rated? Many outlets are only rated at 15 amps, and if you are running the wrong tools at the same time, you'll be replacing a fuse, resetting a breaker or worse an outlet. This could be a real issue if you are in the middle of a cut on one of your last pieces of material, or if the circuit panel is hard to get to.

So then, how do you select a tool if you cannot go by amps? That gets a little harder. The United States is very amp oriented, this amp dependence has been driven by the marketing departments for several of the power tool companies. Many of them have no interest in educating their customers, so it is up to the people who deal directly with the customers. My suggestions would be to look at the other specs provided by the manufacturer. On a reciprocating saw, for example, look at the strokes per minute (SPM), the length of stroke, the amperage, whether it has orbital action and the weight. Using all of these, you can make a better determination whether or not it is the saw for you. The no-load strokes per minute (meaning they count it while the tool is not making contact with any work material) and the stroke length (the total distance the blade actually travels on each cut) determine how quickly a tool can cut. If you are cutting mainly wood, the orbital action simulates the action of a hand saw and cuts wood even faster. The amperage isn't entirely worthless, within one brand of power tools the amperage will show the relative power of this saw compared to the manufacturers other tools. The weight, while it isn't an indication of power, is really important... consider this, would you rather spend 30 minutes holding a 8 lb tool over your head or 28 minutes with a 10-1/2 lb tool? A few more insights on the wonderful world of reciprocating saws can be found on Brian Mark's blog entry from 12/24/2005.

The key to being happy with a power tool is to pick one that meets or just slightly exceeds your needs. By going for the tool with the most power, many people are also going for the tool that costs them the most and wears them out the fastest.

Make a list of the things you do with this type of tool regularly, the things you do relatively rarely and the things you might want to do from time to time. Once you have a list, decide how important it is that the tool you are buying does each one of these. Weigh those items versus fatigue caused by weight, the availability of power and any other special features that could be important to what you intend to do. Then with those considerations in mind, look at the tools and try to match the specifications to your profile of the "perfect" tool. Once you find it, order it.

Almost every major manufacturer of power tools offers at least a 30 day satisfaction guarantee (and usually not the case with air tool manufacturers, strangely). Don't be afraid to use the tool like you will be using it in the field. If it doesn't perform well, you can send it back under the terms of their guarantee. Yes, you will usually have to pay to send an unsatisfactory tool back, but isn't it worth $10 to get the right tool?

Well, I have to be with the family in 10 hours, so off to bed I go. Merry Christmas to all!
Matt G.