The Dangers of Power Tools and Causes of Binding
December 17, 2012
We often hear of the dangers of power tools, but we may not clearly understand the little things that lead up to power tool accidents. All power tools are potentially dangerous given the right circumstances – or should I say wrong circumstances. However, some are obviously more dangerous than others. The more dangerous ones include pneumatic tools such as nail guns, table saws, chain saws, and circular saws.
Why do Circular Saws Bind and How can it be Prevented?
Circular saws in particular can be very dangerous to the DIYer or home-owner. Many people I know think the guard that slides down around the blade is annoying, and I agree. Because of this people tend to either remove these guards or tape or wire them up in a semi-permanent out-of-way position. The danger here is obvious, in that if the saw were to kick back due to binding or similar, you could have a serious accident.
Binding happens when the material being cut pinches the blade from either side as it’s passing through. This is the cause for many accidents related to circular saws, and can actually be avoided very easily. Never attempt to cut through a board that’s not supported sufficiently close to the target cut-line. Why? As the board is cut, its ability to hold itself up in a bridging position is taken away.
The board then begins sagging under its own weight, as well as that of the circular saw, causing the two upper corners of the board to create friction with the saw blade. As more and more of the board is cut, this friction increases, until you have yourself a full-blown binding on your hands. If the binding is sudden, you will most likely get a dangerous kickback, whereas if it’s a slower process, you may just get a strained motor and a lot of smoke.
You don’t want either. An experienced carpenter can usually avoid cases where binding may occur by simply taking away the possibility of downward movement immediately beneath the target cut-line. You can also play it safe by even allowing the presence of a small upward force by supporting the board close to the target cut-line, and letting an appropriate amount overhang on the two ends.
Another way a saw blade can bind is when you’re not firmly holding down the board being cut. By allowing the board to move forward along with the circular saw – even slightly – you can inadvertently allow the board to begin “folding” at the kerf, pinching the rear-end of the saw blade. And you should know that, as with the form of binding I covered earlier, the “bending” of the board that causes the bind is often hardly noticeable with the naked eye.
Power Tool Injuries Stats
We may have heard it said that it’s the more experienced or veteran carpenters that often suffer the worst injuries. This is because as you become more accustomed to a particular routine, you let your guard down and often get careless. If the previous sentence sounds familiar to you, watch out – it’s only a matter of time before an accident will happen. I’m listing some statistics for information’s sake below, (per year, in the US):
Power Nailers – 37,000 to ER
Chain Saws – 36,000 to ER
Table Saws – 29,000 to ER
Snow Blowers – 5,700 to ER
Circular Saws – 10,600 to ER
Riding Lawnmowers – 37,000 to ER
Power Drills – 5,800 to ER
Backhoes – 38 deaths a year
Air Compressors – 2,400 injuries a year
Wood Chippers – 3 deaths a year
As you can see, these are no small numbers. And we’re not talking about little cuts and grazes here either! These are mostly limited to reported cases that put patients into the ER. Power tools with tremendous and limb-lobbing mechanical power are becoming more and more available to folks who, several decades ago, wouldn’t dream of owning such a tool. It follows that many who purchase these tools often don’t take the necessary safety precautions.
Due to their popularity, there are those who may think they know how to operate high-powered tools safely but because they have only the second-hand teacher of observation and maybe some limited experience, they run the risk of injury that could have otherwise been prevented by being better educated or informed. In conclusion, power tools may seem harmless enough, and granted, some are very small and even cute, but they are still very dangerous if not used with care.
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