Channeled quench plates?

Chuck Gedraitis Knives

Chuck Gedraitis Knives

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Dec 10, 1998
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So I had the idea to mill some channels in my aluminum quench plates, maybe 5/32 wide. The idea was to stand a folder blade edge up in the channel for air cooling, pulling heat from 3 sides. I thought that they might act like the condenser on a radiator? I guess if they were milled deep enough an aluminum cover could be placed on top once the blades were placed in.

I was just wondering what others might think about this?
Thanks,
Chuck
 
I think the quenching is over before you get the benefit of the channels . Where they come in handy is on things like my amateur radio equipment where there is a more continuous heat transfer . Those things have cooling fins rather than grooves.
Continuous use might better be done with a water cooled system.
 
I think the problems start coming in if your blade isn't exactly 5/32" thick. Instead of getting relatively full contact on 3 sides, you'd be getting contact on essentially just the smallest side, and little to no contact on the flats.

I would also tend to think that there's probably not going to be a noticeable difference of heat transfer over a 5/32 x 4" (or however long your blade is) cross section of additional contact.

I think your best bet would be to leave your set up as is, and maybe add some forced air cooling between the plates.
 
every now and then i think about building copper faced water cooled Al plates and then it passes as it will not really help my quench speed much more then jsut room temp Al plates. now if i planned on working 3/32 O1 it might be worth it
 
I've often wondered how much sense it makes to plate quench an object that is tapered to each end.
Contact in the middle, none anywhere else.
The physics of plate quenching don't quite add up, to me, though the window of time is so (compared to simple steels) long that it kind of doesn't seem to matter all that much what you do.
My last batch of D2 blades were oil quenched in the packets and so far I'm extremely pleased with the edge quality.
 
My main concern is keeping blades straight. When I plate quench I sometimes get some warp and I thought that standing blades on their spines would help alleviate that. Some makers just air cool with no plates and I believe that cooling faster is better.
 
I'm just a beginner, but can't seem to find a way around straightening each one as it cools, as the martensite is still forming. It'll be cool to see what people have tried that gets around that!
Please take photos if you try the channeled cooling block, can't wait to see how it works!
 
Faster is not better in many cases. When there is a phase transformation involved, slower is better.....as long as it gets done in the time needed for the transformation. For air cooling and stainless steels ( you didn't say what you are working in), that is a long time. Air cooling in still air while hanging from a wire will be probably the safest method for small thin blades.

That said, normal plate quenching between flat aluminum plates is pretty warp free if you adjust the plates so they contact as much of the blade as possible. I often use coins as shims to make the plates clamp at the right angles to match the blade. I do this as a dry run before I heat put the blades in the oven and make notes where to place the coins for each blade.
Additionally, quench plates don't normally serve any quenching function, they only serve to maintain the blade straight as it cools. For small blades that will be made repeatedly, you might be far better to make smaller fitted aluminum plates with a hinge to set the blade in and clamp it down with a spring clamp while it cools. After the blade has cooled and been removed, a quick dip in a bucket of cool water will have it ready for the next blade. For folder blades 1/2" thick and 2X4" would work fine.
 
Heck, taking that one step farther, you could mill the blade shape into the plates and have them clam shell close for 100% contact.
 
Stacy, is there a down side to quenching in oil (canola in this case) to get beyond the curve, then stripping the foil and straightening? Almost all my blades are either distally tapered, or tapered in all directions, so I thought that plates weren't ideal since there's no contact (great tips about the coins).
The quench is intended to get beyond the curve so I can check straightness with heavy gloves, but perhaps I'm cooling too fast- mostly working with CPM d2 and 440c.
Apologies to all if I'm taking this thread in a different direction...
 
bladsmth said:
Faster is not better in many cases. When there is a phase transformation involved, slower is better.....as long as it gets done in the time needed for the transformation. For air cooling and stainless steels ( you didn't say what you are working in), that is a long time. Air cooling in still air while hanging from a wire will be probably the safest method for small thin blades.

That said, normal plate quenching between flat aluminum plates is pretty warp free if you adjust the plates so they contact as much of the blade as possible. I often use coins as shims to make the plates clamp at the right angles to match the blade. I do this as a dry run before I heat put the blades in the oven and make notes where to place the coins for each blade.
Additionally, quench plates don't normally serve any quenching function, they only serve to maintain the blade straight as it cools. For small blades that will be made repeatedly, you might be far better to make smaller fitted aluminum plates with a hinge to set the blade in and clamp it down with a spring clamp while it cools. After the blade has cooled and been removed, a quick dip in a bucket of cool water will have it ready for the next blade. For folder blades 1/2" thick and 2X4" would work fine.
Click to expand...
most of the PM SS we use these days have both air cool and oil quench specs in the data sheet and nearly all of them sho to get harder with the oil quench (more complete martinsite transformation) so simply pulling out of the kiln and air cooling is not the best. even tho it makes it under the curve.

grinding tapered tangs and full bevels hinders contact with the plate and destroys any straightness advantage of plate quench. it also makes for less contact to the plate and hurts quench speed. know the quenchant and work with it. its all about contact, conductivity and mass.
when i plan on plate quenching a blade i grind maybe half inch bevels or less depending on steel and never taper the tang or blade. 99% of the time they come out of the plates dead flat.

saying quench plates dont serve any quenching function just goes to show you are not using them as a quenchant. they do in fact quench faster then air cooling when used right. lets not misslead someone that might be reading this later
 
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