Multifunction Divider/Compass

[CedarSlayer]

Hex keys are brilliant for making blades out of. If you use 1/4" or larger, forgive me for being imperial, they are also fairly stable. Because of the bend you can make very low angle planes out of them for various contours. The next tool I post will show how I haveused them.

Roll pins can also be sharpened to make superb blades for cutting gauges and the like.

Another great source for hardened metal is cheap knives and scissors.

Fairly recently China developed a new method for mass producing stainless steel that is capable of producing amazingly good tool steel. Since the limiter for price is quantity often the make huge batches of top notch steel due to one request and then fill the rest of their requests with steel that is way over spec. If you find a deal on a good stainless knife, test it for edge retention, ease of sharpening, and it's ability to form a bur (work hardening) Use a cheap stone initially to test. Some stainless will gum up a sharpening stone and make it near useless.

Stainless is so complicated to heat treat, that you might as well obtain it tempered.

My trick to grinding hardened steel without ruining the temper is to use a plant fiber paint or oil brush. I wet the brush and put it on the tool as I grind. When the water starts to boil, I back off on the tool and wet the brush again. This way the tool angle and position are preserved and the tool never gets above boiling. It does eat brushes, but natural fiber brushes bought bulk are very inexpensive.

Bob