When using a file to test for hardness, use this edge: This helps prevent damage to your file’s teeth.
Miscellaneous Metallurgy Resources
Metallurgy of Steel for Bladesmiths & Others who Heat Treat and Forge Steel by John D. Verhoeven | Mirror
Engineering Handbook (Contains lots of metallurgical goodness)
Melting temperatures of various metals
Shibuichi Alloying Calculator (Enter pour amount value, it does the rest. It is ratio based, so these are approximate values, mainly if you are using sterling instead of 999 silver. Make a copy of the sheet to your docs to edit.)
Comprehensive guide for metal etchants