I am a new apprentice smith and I have enjoyed reading this forum for ideas and solutions for problems. Here is one and I don't know how I did it and I think I know the solution but want to ask before I do it. I bought some Aldo's 1084 steel to make skinners and small hunters. I made a small hunter and shaped, normalized (checked the magnetization) for the 3 stages, yellow, red and black/red. I then ground the blade down to the profile that I wanted. Here is my question. When I went to drill the pin holes into the tang, it was to hard, the bit would only go in 1/6 of an inch at any given area of the tang, period. Thought it was a bad bit, tried two more bits, same thing. I grabbed some ALdo 1084 that I have not used yet and the same bits went straight thru the metal. I have NOT quenched or annealed the metal yet. I assume it got some Rockwell somehow, somewhere, and I may need to Drawback the the tang like you would the spine of the knife when doing a large hunter. Thanks for the suggestions and help in advance.
Putting the flack vest and helmet on.
Hello Douglas, Normalizing involves taking the blade to full solution, subsequent air cooling produces pearlite (lamellar structures)as the carbon comes out of solution. What this means is that the carbon will concentrate and bond with iron to form sheets of iron carbide, so for the most part you are drilling through soft iron until you hit a sheet of pure carbide, which nothing but a diamond can stand up to. To drill this you need to get rid of that carbide sheet. You can heat it to blue or even dull red many times and still have a carbide cluster there that will laugh at your drill. What you really need to do is dissolve that carbide cluster and put it back into solution and then keep it from clustering up again. This may sound crazy but for this the best way to get that spot drillable is to first harden it. Heat the drill spot to well beyond non magnetic and then air cool, then reheat to just non-magnetic and quench it in oil. Then reheat the spot two or three times to dull red, but always still magnetic.
What this process will do is dissolve the carbide and disperse it a bit, then the reheat and quench will dissolve it again but this time not allow it to form carbide at all by trapping it in solution with the quench. Then the dull red heats will bring it out of solution in the form of tiny spherical carbide that are evenly scattered rather than gathered into sheets. These tiny carbides will easily push aside during drilling.
"One test is worth 1000 'expert' opinions" Riehle Testing Machines Co.
Thank you, Mr. Cashen for your reply and explanation. I have always been a little fuzzy about pearlite, I now have a enjoyable to-do-list, that is sitting next to my honey-do list since today starts my weekend.
