bmazingo Posted February 12, 2011 Share Posted February 12, 2011 Hey guys, I know this has probably been posted before, but the search function just doesn't like me like me today. I forged a blade from a saw mill canter head blade, but I cannot get it soft enough to drill. I do not know what steel it is, but I assume it may be tool steel and given the trouble I am having it maybe airhardening. So I tried heating it past non magnetic(more heat on the area to be drilled) then put it in a bucket of vermiculite overnight. I placed two other pieces of hot steel in with it because the night time temperatures are in the 20's here. so I checked it this morning still very hard. File just slides off and can't even get a center puch to leave good dimple. I have already broke one blade forged from an unknown steel, and I was wanting this one to survive. I can change my handle material If I can't get it drilled. Please post any ideas, I'm gonna keep reading. Quote Link to comment Share on other sites More sharing options...
MattBower Posted February 12, 2011 Share Posted February 12, 2011 Try tempering it at a dull red without going above non-magnetic. Hold it there for an hour, or at long as you can stomach, then let it air cool. Again, keep it below non-magnetic during the whole process. See what happens. Quote Link to comment Share on other sites More sharing options...
nhblacksmith Posted February 12, 2011 Share Posted February 12, 2011 You can always hot punch the holes. That will likely leave a very slight bulge on the sides of the handle tang but they are easy to grind back flat. Quote Link to comment Share on other sites More sharing options...
bmazingo Posted February 12, 2011 Author Share Posted February 12, 2011 I don't think I can hold a dull red for 1 hour, I have never tried to run my forge that low, my or may not be possible. Hot punching may be a solution. Quote Link to comment Share on other sites More sharing options...
jimmy seale Posted February 12, 2011 Share Posted February 12, 2011 what type of drill bits are you using? may need a better bit say in the tungston/carbide or maybe drill speed, or pilot hole may help, good luck, jimmy Quote Link to comment Share on other sites More sharing options...
MattBower Posted February 12, 2011 Share Posted February 12, 2011 I certainly understand wanting to save this one, but I have to point out that this is one of the problems with using mystery steel. Long, slow anneals like you did are actually counterproductive with some steels, and of course if it's air hardening things are even worse Quote Link to comment Share on other sites More sharing options...
David Ab Posted February 13, 2011 Share Posted February 13, 2011 I haven't tried this, so I don't know if it works, but there's information on the web about putting a grinder to a piece of metal and telling what sort of metal it is by the color, length, and "branching" of the sparks. Another option would be to ask one of the metallurgists on this or another forum what type(s) of steel were commonly used for that kind of saw blade. For drill bits you could try Harbor Freight's cobalt bits, which are surprisingly cheap and work quite well. I'd use a drill press at slow speed, and maybe a bit of oil to keep the hole cool. Good luck! Quote Link to comment Share on other sites More sharing options...
bmazingo Posted February 13, 2011 Author Share Posted February 13, 2011 I haven't tried this, so I don't know if it works, but there's information on the web about putting a grinder to a piece of metal and telling what sort of metal it is by the color, length, and "branching" of the sparks. Another option would be to ask one of the metallurgists on this or another forum what type(s) of steel were commonly used for that kind of saw blade. For drill bits you could try Harbor Freight's cobalt bits, which are surprisingly cheap and work quite well. I'd use a drill press at slow speed, and maybe a bit of oil to keep the hole cool. Good luck! It is deffinately HC steel, a center punch will not even dimple it. I have a cobalt bit gonna try the red heat anneal first if that doesn't work, I can try the hot punch method, or just wrap the handle in leather. Quote Link to comment Share on other sites More sharing options...
Nathan Hall Posted February 15, 2011 Share Posted February 15, 2011 If you cant get the steel workable, and the other things mentioned have failed, then you could always stop by your local machine shop and have them pop the holes in real quick, nothing a carbide end mill couldnt handle fairly easy id say, and unless they are just covered up busy, which no shop in the country is these days, then it shouldnt cost much at all, Id guess between 10-20 bucks tops for two small holes in something as thin as a knife handle, if you have a cheap source you can actually put a carbide spotter drill, or a ball nosed endmill in a drill and do a servicable job with out a mill if you had too. Quote Link to comment Share on other sites More sharing options...
bmazingo Posted February 15, 2011 Author Share Posted February 15, 2011 If you cant get the steel workable, and the other things mentioned have failed, then you could always stop by your local machine shop and have them pop the holes in real quick, nothing a carbide end mill couldnt handle fairly easy id say, and unless they are just covered up busy, which no shop in the country is these days, then it shouldnt cost much at all, Id guess between 10-20 bucks tops for two small holes in something as thin as a knife handle, if you have a cheap source you can actually put a carbide spotter drill, or a ball nosed endmill in a drill and do a servicable job with out a mill if you had too. Good Ideas! I actually debated buying a straight drill(bit) used for drilling carbides. But $40 is a little steep with work being slow. On the brite side I managed to hot punch the holes in the tang. I used a good quality punch to make my marks in the hot steel. Then I used a cheap (very cheap) punch to finish the holes. Came out good. Bad news is my blade developed cracks either beore or when I quenched it.(sickening) I figure I over worked the steel or worked it a little too cold. I know I did not normalize it. Fortunately the blade is still in one piece and the cracks are small and in the false edge only. I hit it several times on my anvil and threw it on the cement, nothing happened. I am probably gonna finnish it with a quick handle and use it for a utility knife. I blame it on my inexperience and lack of knowledge when it comes to working steel like this. It just reinforces the fact that learning the steel's properties is very important. I am gonna concentrate on learning the basics and stick to steel I know will survive my newbie-ism....like sawmill bandsaw blade, good for everything from spoons to knives. lol. Quote Link to comment Share on other sites More sharing options...
MattBower Posted February 15, 2011 Share Posted February 15, 2011 From your description it was likely air hardening, which would explain why it didn't like the quench. Quote Link to comment Share on other sites More sharing options...
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