Quote:
Originally Posted by theodog
Am I correct to believe that "bright" steel is High carbon?
I am just using black for learning -cheaper.
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The carbon content is the element that govern whether a steel will harden. There is a heap of other elements that can be thrown in to the crucible to offer additional attributes to a steel depending on it's intended use.
if it's sold as "black" then it's mild steel (low carbon) steel. But mild steel can have the black scale chemically removed and is sold as "bright". "bright" steel can also mean "free machining steel" this stuff has lead in it and will never harden.
high carbon steel comes coated in the black scale and you'll soon know you are working with something very different as it's much tougher. High carbon steel is also sold as "silver steel" which has been centerless ground to incremental diameters.
If you buy it from a merchant then you can be assured that what they say it is will be correct, however if you pick up something that's been laying around it's sometimes very difficult to tell what it is. There are tricks to indicate...
- high carbon steel is much tougher to machine
- when ground (on a bench grinder), mild steel sparkes are long, redish and streaky while high carbon steel sparkes much brighter, yellow and almost incandecent. Try this, take a piece of something you know is mild steel (angle iron) and an old file. Go to the bench grinder and compare the sparkes made when ground.
Bottom line. Before you spend time making something, take a small piece and heat it to bright red and throw it into water. (take care) Can you file it? (use the old file) BTW, when steel gets to the 'right' temperture for quenching it looses it's attraction to magnets.
I may look into a 150-180 tooth wheel.
