Me spark testing

Just out of of curiosity I wanted to do some spark testing of some scrap steel I had in my work shop. It felt like discovering hidden treasure, I found some decent pieces for what I would be making.Here below are some pictures of what I used as a guide.

http://maritimesecurity.asia/free-2/maritime-security-asia/how-to-identify-metals-in-engine-room-observation-and-spark-test/

http://www.tpub.com/steelworker1/5.htm