.150" Post HT Grinding

DustinY

DustinY

Joined
Dec 29, 2016
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754
So, I know that most people typically grind stuff down below .100 after HT and above post HT, but my question is can I grind .150 post HT without issues to the integrity of my HT, etc?

The stuff i've picked up are that people choose to do it this way to deter warps, i'm concerned i won't get even grinds, and would rather grind post HT as I think it's easier.

Please advise :)
 
If you use fresh ceramic belts you won’t have any problems with heat. Just dip it in water every couple passes to keep it cool and change belts when it starts heating up too quick.
 
If this is the method you intend to use for ALL future grinding it would be wise to research "Mist/Water" cooling systems.
 
Busto said:
If this is the method you intend to use for ALL future grinding it would be wise to research "Mist/Water" cooling systems.
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This is quality advice. I’ll do so, been on the to do list actually.
 
+1 on what others have said regarding using fresh sharp belts and dipping after every pass. So yes you can grind all that post HT but you really don't need to. If you want to give yourself some wiggle room grind pre HT down to 0.05" and then grind the rest post HT. If you've got a warp severe enough to require you to have 0.15" thick steel you've got other problems. :-) Most warpage can be dealt with by clamping during tempering.
If I'm starting with steel that is 0.09" or thinner I profile/drill only and do all grinding post HT. If it's thicker I will do partial pre HT grinding and the rest post HT.
Just another note regarding post HT grinding. You're more likely to overheat your steel with the finer grits because there is more surface area. So I really make sure to use fresh belts here, dip frequently and slow my grinder down.
 
Robert Erickson said:
+1 on what others have said regarding using fresh sharp belts and dipping after every pass. So yes you can grind all that post HT but you really don't need to. If you want to give yourself some wiggle room grind pre HT down to 0.05" and then grind the rest post HT. If you've got a warp severe enough to require you to have 0.15" thick steel you've got other problems. :) Most warpage can be dealt with by clamping during tempering.
If I'm starting with steel that is 0.09" or thinner I profile/drill only and do all grinding post HT. If it's thicker I will do partial pre HT grinding and the rest post HT.
Just another note regarding post HT grinding. You're more likely to overheat your steel with the finer grits because there is more surface area. So I really make sure to use fresh belts here, dip frequently and slow my grinder down.
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I send out for my HT’ing and if I develop a warp post HT grinding (which is frequent, I don’t know what to do to fix it). I know you can temper it as many times as you need, but how much do I shim and over adjust, and I don’t know what kind of protection I can for using my kitchen oven to prevent it from the temperature spikes. Massive cast iron or Dutch oven? Maybe I’ll try a couple pre-HT.
 
From what I see, there are two reasons for grinding AEB-l post HT. The first and most critical is the warping issue. It will be easier to straighten if the bevels aren't ground and you may get less warping as it'll clamp flat in your quench plates. Depending on how high your bevels are, you wont get full contact with bevels.

Another reason I like to grind post HT is that to me, AEB-l feels gummy when grinding pre HT. Hard to describe but it just seems to grind easier post HT as the belt skates easier where as it grabs pre HT making it harder to control the grind. This is my own experience but others have said they notice the same thing.
 
scott kozub said:
From what I see, there are two reasons for grinding AEB-l post HT. The first and most critical is the warping issue. It will be easier to straighten if the bevels aren't ground and you may get less warping as it'll clamp flat in your quench plates. Depending on how high your bevels are, you wont get full contact with bevels.

Another reason I like to grind post HT is that to me, AEB-l feels gummy when grinding pre HT. Hard to describe but it just seems to grind easier post HT as the belt skates easier where as it grabs pre HT making it harder to control the grind. This is my own experience but others have said they notice the same thing.
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This is what I have noticed as well. It is gummy pre HT and I much prefer the feeling of grinding post.
 
I don't think I'd do additional tempers for warp correction. I assumed incorrectly that you were doing the HT. Whether you grind some pre HT or all post HT you are potentially going to face this.
The warping during post HT grinding can be minimized by grinding alternate sides every pass so you're taking material off symmetrically and by minimizing heat build up by sharp belts and frequent dipping.
In my experience I've only found this post HT warping to be an issue with thin stock. Stock that's 0.15" shouldn't be warping after HT unless you're building up significant heat.
 
Robert Erickson said:
I don't think I'd do additional tempers for warp correction. I assumed incorrectly that you were doing the HT. Whether you grind some pre HT or all post HT you are potentially going to face this.
The warping during post HT grinding can be minimized by grinding alternate sides every pass so you're taking material off symmetrically and by minimizing heat build up by sharp belts and frequent dipping.
In my experience I've only found this post HT warping to be an issue with thin stock. Stock that's 0.15" shouldn't be warping after HT unless you're building up significant heat.
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I haven’t tried .150.

.135 warped and I’m using fresh belts and not building up heat, I grind with my hands on the bevel. It was also more of an issue with the .100 thick steel. I might try correcting it, but it does suck. Maybe the kool mist - I dunk after every pass too. Idk.
 
DustinY said:
I haven’t tried .150.

.135 warped and I’m using fresh belts and not building up heat, I grind with my hands on the bevel. It was also more of an issue with the .100 thick steel. I might try correcting it, but it does suck. Maybe the kool mist - I dunk after every pass too. Idk.
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Hmm it sounds like you're doing all the right things, I'm not sure what else for you to try.
 
Some steels require faster quenches than just air cool, such as 20cv, or z-wear. I plate quench them, and grind post HT. Sucks on belts, but I can tell a difference with fine edge stability if I grind bevels in pre HT. With shallow hardening steels, I will at minimum do a Scandi grind, quench, then finish grind after HT.
 
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