Hi,
On the weekend, I planned to make some hooks for bowl turning on a bowl lathe from some coil springs. I heated the springs in a coal fire with air blowing through it from a vacuum cleaner. At first, the straightening of the spring seemed to be going well; I was hating one end, placing over a metal post in the ground, and pulling to form a straight rod. On the third heating however, I went to pull the spring out of the forge, and it came apart into two pieces. Once cooled, the broken end seemed to have a very grainy texture (see photo). I promptly gave up, as I was worried that I might have got hold of the wrong coil spring.
I would appreciate your input on this. Is this grainy texture normal, or is it a sign that the steel is not good enough to make tools with? I am also wondering why the spring came apart in the way it did? I suppose there was a chance that the spring had a preexisting weakness (it was from a used car). Finally, do you think it is worth persisting with the spring, or should I find another or fork out for some proper tool steel?
Thanks in advance,
Cabbages