Jim Moenck
Well-Known Member
One of my New Year’s resolutions was to really work on my heat treating of blades.I know this was something I need to get better at, so I can get consistent results on the metals that I use.
Well, I’ve hit a wall and I need some expert advice. I’d sure appreciate any help and/or insight that you can give me.Here is a synopsis of what I’ve done, and where the problem is.
The material is W2. I bought this quite a few years ago from Don Hanson, so I know it is good stock.It is 2-1/8” round stock. I heated it in my forge and used my press to make it into a manageable size.Finished stock at this point is about 3/16” x 1-1/4”.I forged 6 small blades out of it, from about 2-1/2” to 3” in length. The blades were brought up to just past magnetic and put in a pail of vermiculite to cool overnight.
The blades were ground smooth for heat treat.I have a Paragon furnace with an analog control, yes it is old. The temp setting dial and the thermometer readout do not match, and I have to set the dial higher to get to the desired temperature. I have a digital readout and thermocouple that I tested the furnace with, and I believe the thermometer on the furnace is close to accurate, but I can’t be sure just how close. I heat treated each one just a bit different to try to get the process dialed in.On this first round, I used peanut oil heated to 150 degrees as my quench.Blades were heated differently, from 1425 to 1475, and were soaked for 10 minutes. Then they were tempered for one hour at temps ranging from 350 to 450 degrees.
I took these to a friend’s shop to be tested for hardness. He set the tester using the factory rated test blocks, and checked it again after testing the blades to verify that it was correct.The blades were very inconsistent, and not nearly as hard as I expected; mostly in the 40’sand 50’s RC.What we found strange was the variance in almost every blade.Fromthe ricasso to mid-blade to tip varied from 4 to 16 points RC. Also, blades that were heated to the same temp, quenched and then tempered at increasing temps did not progress the same.I would expect blades treated at 1450/375 to be harder than at 1450/400, and those should be harder than 1450/425 but that was not the case.
I picked up some Parks #50 to see if my quench was the problem. I heated it to 100 degrees, did the same type of regimen expecting better results. I was disappointed again. I still had the big variances within the same blade. I would expect the blade to be within a couple of points at whatever temps I use and would just have to find the “right”combination to get the desired RC. Ireally expected 1460 and a 425 temper to get an even and repeatable RC61 or 62.
Can anyone give me some insight as to what I might be doing wrong? I am changing my Paragon to a digital readout to get a more accurate measure, but I don’t think that is theproblem.
Any thoughts??????
Well, I’ve hit a wall and I need some expert advice. I’d sure appreciate any help and/or insight that you can give me.Here is a synopsis of what I’ve done, and where the problem is.
The material is W2. I bought this quite a few years ago from Don Hanson, so I know it is good stock.It is 2-1/8” round stock. I heated it in my forge and used my press to make it into a manageable size.Finished stock at this point is about 3/16” x 1-1/4”.I forged 6 small blades out of it, from about 2-1/2” to 3” in length. The blades were brought up to just past magnetic and put in a pail of vermiculite to cool overnight.
The blades were ground smooth for heat treat.I have a Paragon furnace with an analog control, yes it is old. The temp setting dial and the thermometer readout do not match, and I have to set the dial higher to get to the desired temperature. I have a digital readout and thermocouple that I tested the furnace with, and I believe the thermometer on the furnace is close to accurate, but I can’t be sure just how close. I heat treated each one just a bit different to try to get the process dialed in.On this first round, I used peanut oil heated to 150 degrees as my quench.Blades were heated differently, from 1425 to 1475, and were soaked for 10 minutes. Then they were tempered for one hour at temps ranging from 350 to 450 degrees.
I took these to a friend’s shop to be tested for hardness. He set the tester using the factory rated test blocks, and checked it again after testing the blades to verify that it was correct.The blades were very inconsistent, and not nearly as hard as I expected; mostly in the 40’sand 50’s RC.What we found strange was the variance in almost every blade.Fromthe ricasso to mid-blade to tip varied from 4 to 16 points RC. Also, blades that were heated to the same temp, quenched and then tempered at increasing temps did not progress the same.I would expect blades treated at 1450/375 to be harder than at 1450/400, and those should be harder than 1450/425 but that was not the case.
I picked up some Parks #50 to see if my quench was the problem. I heated it to 100 degrees, did the same type of regimen expecting better results. I was disappointed again. I still had the big variances within the same blade. I would expect the blade to be within a couple of points at whatever temps I use and would just have to find the “right”combination to get the desired RC. Ireally expected 1460 and a 425 temper to get an even and repeatable RC61 or 62.
Can anyone give me some insight as to what I might be doing wrong? I am changing my Paragon to a digital readout to get a more accurate measure, but I don’t think that is theproblem.
Any thoughts??????
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