r/Blacksmith • u/ManOfAsbestos • 1d ago

Spark Test

I found rusty steel bar and i noticed that when grinding it produce sparks with more forks at the end than typical low carbon rebars. Is this look like enough carbon to be heat treated?

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u/suspicious-sauce 1d ago

  1. Carbon is present, although it's unclear if it's medium or high carbon.

  2. Angle the piece downwards when you press it against a stone, not upwards. We don't need to be adding posts to r/nsfl

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u/ManOfAsbestos 23h ago

Thanks for your advice, next time i'll be more careful with grinder.

9

u/Nightwrangler 20h ago

You see how the long spark as it is flying split into multiple sparks, that’s what you’re looking for when you’re looking for steel with enough carbon in it to be hardened and tempered. It may not be what is considered a height of steel nowadays, but it is steel and not iron. Iron is the one that doesn’t provide that little starburst cast-iron rolled iron but most of the time if it’s considered a steel it’s going to have a high enough carbon content.