Spark testing of ferrous materials, I am not good at it!

I can see “sparking” differences between various iron-bearing metals, but I wouldn’t stake my life or anybody else’s on using spark testing to determine a sample’s exactmakeup.
Here’s my short video to show what I mean, and then, at the end, my own conclusions:

Pete Stanaitis


That was interesting Pete. I don’t know one steel from another and the only place I’ve seen spark testing is on the Forged in Fire TV show. You obviously know your way around. The only steels I’ve had for forging are leaf springs, torsion bars and axles. I know you can make good blades out of them but I don’t have a clue what numbers they are. I don’t know what those Rebak cutters are made from but it seems like truck leaf springs would be a steel that could be used I guess depending on what size the cutter needed to be.


In all the DIY rebak videos I’ve seen they’re too hard for drill bits. They use either a plasma cutter or a cutoff wheel. Pretty high carbon stuff I would think.


I suspect that 5160 (much of leaf spring material is this) would work okay, but the S series tool steels,
(“Shock Resisting”) , especially S5 or S7 would be better.