Anneal?

D

DustinHall

Joined
Dec 31, 2008
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Should I anneal or normalize precision ground 01 bar stock (I use stock removal) before I quench or does it not matter?
 
Probably not needed unless you really hog off material when grinding.If you have a problem just stress relieve/temper at about 1100-1200 F.
 
Dustin, mete is right. You have a good anneal on it to begin with. Grind evenly taking your time for precision and keep things cool and you should do just fine.
 
I have a similar question.

When you say to "keep things cool", how cool is that.

I annealed and old file, used a bench grinder and had files to shape and do the bevels.

If I got it too hot doing the bench grinder, do I have to anneal it again before hardending ?
 
I don't understand why it would matter if you get the steel hot while grinding before you heat treat. In my mind, once it's heating up to be quenched, any heating done to the steel from grinding would be undone. If someone could explain this that would be nice.
 
This is a bit of an answer, and a question for Mete', or Kevin. I can't explain why, but I can tell you that, for instance, if you were to get it really hot while grinding, and you do not normalize, and or heat cycle afterwards, it is going to warp in the quench, because the heat it recieved is not going to be an even heat, and this will put uneven stresses in the steel that seem to hang around even though you have soaked it at quench heat before quenching. I have recently started doing a double heat cycle at 1200° before the high temp soak, and that has cured most of my blades from warp so far. I let the blade cool to room temp between cycles, then take it on up to 1475° for a twenty minute soak before the quench. Kevin, Mete' is there anything else that could, or should be done, or am I wasting my time doing that? I stock remove PG 01. HT with an Evenheat oven, quench in Parks AAA at 130°.
 
You definitely don't have to fully anneal before HT, but a normalization or stress relieving cycle would be good. On some blades I had issues with, I stress relieved at 1200F for about 2 hours prior to heat treating, and I had no further problems. One cycle of stress relieving should be adequate, I would think.

--nathan
 
Angus McGunnigl said:
I have a similar question.

When you say to "keep things cool", how cool is that.

I annealed and old file, used a bench grinder and had files to shape and do the bevels.

If I got it too hot doing the bench grinder, do I have to anneal it again before hardending ?
Click to expand...

I would say too hot would be when you see the steel change colors. Anything cooler than that should be fine. Someone correct me if I'm wrong.
 
Exactly, if you are turning colors you are making changes in the steel, changes that could resurface in the final heat treatment. My rule of thumb for any grinding, before or after heat treatment, is if you can't hold the steel in your bare hands you need to dip it. I have never understood the need for folks to turn steel blue when grinding. Not only is heat bad for the condition of the steel, it is bad for belts and will shorten their life, it is bad for you if you get burnt or cannot keep a good grip on the blade during grinding, amd finally it is bad for the blade if you cannot keep constant control over the grinding technique. Good grinding techniques are more a matter of finesse and precision than clumsy bulk hogging. You need enough pressure to properly engage the abrasive, but of you are taxing the motor and turning the steel blue you may want to reassess your methods. I like to say that I prefer to do heat treating in a salt bath or oven and not on the grinder.
 
Kevin R. Cashen said:
My rule of thumb for any grinding, before or after heat treatment, is if you can't hold the steel in your bare hands you need to dip it.
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Agreed. By doing this, I've modified a couple of factory knives, and ground blades from tempered files without any problems. I'm so picky I dip in water even before it gets that hot, when working on HT'd steel. Be extra careful near the tip and edge, naturally.
 
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