It's the most common tool on the planet. The flat head is also one of the most abused tools, often substituted for any number of other tools that might not be available. The fact is the flat head screwdriver is quite useful for more than tightening screws. Used for light prying, scraping, nudging or holding it can be pretty versatile. Treat it too badly, though, and it'll snap, leaving you with a fishing weight in your toolbox.
There are flat head screwdrivers in many sizes, so choose the one in your tool box which most closely matches the job you need to do with it.
Check out a picture of a flat head screwdriver.
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