I hate these things!
But, you find them everywhere. Craftsman used them for the drain plugs on the engines and trans-axles. I just acquired an older Craftsman GT and went to drain the oil from the trans-axle only to find that someone had rounded off the head. I've been using this for years and I'm surprised more people don't know about this little trick. The disc brakes on GM products require a special tool to pull apart or you can use a Allen head socket. On this one it had been rounded to the point I had to tap it on but, just reverse the usage. Put the 3/8's square over the plug and the use a 3/8th socket or wrench to loosen and remove. No more rounded off corners
earthgrinder, BolensBug, kdubban and 1 other said thanks