The "Ask Nathan a Question" Thread

Hi Nathan. I have been scouring BF and trying to figure out your heat treat for D2. I plan on trying out PSF27 soon when I can find it. And have consistently heard about your heat treat being the best. Currently I use Peters, but want to get an oven soon.

I dont want to step on toes so to speak, but I'm trying to figure out if what I have found is correct.
I can PM you details or add what I have found here.

So far it seems like:
(Unsure of ramp temp if needed)
1850°F (hold for minimum soak)
Quench
Cryo
Low temper at least 2x?
If you want me to edit this out I can.

Also it was great meeting you at bladeshow with some of my friends!
Thank you for your time.
Any advice will be greatly appreciated.
 
ShannonSteelLabs said:
Hi Nathan. I have been scouring BF and trying to figure out your heat treat for D2. I plan on trying out PSF27 soon when I can find it. And have consistently heard about your heat treat being the best. Currently I use Peters, but want to get an oven soon.

I dont want to step on toes so to speak, but I'm trying to figure out if what I have found is correct.
I can PM you details or add what I have found here.

So far it seems like:
(Unsure of ramp temp if needed)
1850°F (hold for minimum soak)
Quench
Cryo
Low temper at least 2x?
If you want me to edit this out I can.

Also it was great meeting you at bladeshow with some of my friends!
Thank you for your time.
Any advice will be greatly appreciated.
Click to expand...

It's a simple question but the answer is not. Depending on your oven you can get hot spots on ramp up which will react differently if you're using a prequench. Your particular D2 will pre-quench differently also, depending on who made it and how. There are too many variables to go into here. For information on pre-quenching I recommend tool steels 5th addition, if you have it. If you don't, the process is the same, you have to sneak up on the optimal microstructure going into the main austenitizing step because if you exceed it you'll blow the grain. This can be found through experimentation. Fortunately you don't need to maximize the grain refinement, you're more interested in getting the carbon into even solution (D2 can be very highly spheroidized, the most I've ever seen, which can play hell on edge stability) to reduce your second heat, so you can use conservative numbers. 1700 won't do much but it won't hurt anything either.

If your oven isn't up to the task (100F hot spots) you can chase your tail with pre-quench. If you're not using a prequench then it still depends on your oven. The safest thing to do would be overheat the empty oven 100F for an hour, turn it off and load your work, turn it back on at the correct temp, soak ~35 minutes at 1850, relatively rapid quench, direct into non-contact (not wet) cryo then tempers gives a good basic HT for D2 that isn't completely optimized but is safe and performs well. Cheap oven tend to mess up the steel during ramp up, not the soak. If you're running a good oven then yes, use a standard two stage pre-heat. This will reduce your soak time 5-10 minutes, but really D2 is pretty tolerant of a long soak (but not a short). I recommend 30 min minimum once at temp.

You can play with that aust temp a lot. The higher you go the more RA you have to deal with, but a good quench and cryo is pretty effective, though you need to experiment to assure you're addressing it. Different blade geometry quench differently. I think the best experiment is controlled edge angle comparative cut testing in controlled media against known standards using light and magnification. It shows up very easily there. Again this can be found through experimentation. I have D2 platens here (with course grain) at HRC 65 after high temper that were austenitized at 2050! Just don't over do it if you're using the prequench because there is less carbide to pin the grain. 1850 is a good starting point.

I wish I could give you an exact process, but there is enough variation in D2 that there isn't an exact protocol, just a starting point.
 
Nathan the Machinist said:
It's a simple question but the answer is not. Depending on your oven you can get hot spots on ramp up which will react differently if you're using a prequench. Your particular D2 will pre-quench differently also, depending on who made it and how. There are too many variables to go into here. For information on pre-quenching I recommend tool steels 5th addition, if you have it. If you don't, the process is the same, you have to sneak up on the optimal microstructure going into the main austenitizing step because if you exceed it you'll blow the grain. This can be found through experimentation. Fortunately you don't need to maximize the grain refinement, you're more interested in getting the carbon into even solution (D2 can be very highly spheroidized, the most I've ever seen, which can play hell on edge stability) to reduce your second heat, so you can use conservative numbers. 1700 won't do much but it won't hurt anything either.

If your oven isn't up to the task (100F hot spots) you can chase your tail with pre-quench. If you're not using a prequench then it still depends on your oven. The safest thing to do would be overheat the empty oven 100F for an hour, turn it off and load your work, turn it back on at the correct temp, soak ~35 minutes at 1850, relatively rapid quench, direct into non-contact (not wet) cryo then tempers gives a good basic HT for D2 that isn't completely optimized but is safe and performs well. Cheap oven tend to mess up the steel during ramp up, not the soak. If you're running a good oven then yes, use a standard two stage pre-heat. This will reduce your soak time 5-10 minutes, but really D2 is pretty tolerant of a long soak (but not a short). I recommend 30 min minimum once at temp.

You can play with that aust temp a lot. The higher you go the more RA you have to deal with, but a good quench and cryo is pretty effective, though you need to experiment to assure you're addressing it. Different blade geometry quench differently. I think the best experiment is controlled edge angle comparative cut testing in controlled media against known standards using light and magnification. It shows up very easily there. Again this can be found through experimentation. I have D2 platens here (with course grain) at HRC 65 after high temper that were austenitized at 2050! Just don't over do it if you're using the prequench because there is less carbide to pin the grain. 1850 is a good starting point.

I wish I could give you an exact process, but there is enough variation in D2 that there isn't an exact protocol, just a starting point.
Click to expand...
thank you for the answer.
A bit more than I expected. I will continue doing my research. The goal is to optimize it as best as I can. So I guess once I get my oven I will have to do a bunch of experimenting.

From that it seems like I will try prequenching, but skip the ramp prior to austenizing, then follow the rest of the heat treating protocol. I will likely use Aluminum plates for quenching.

Thanks for the help!
 
Nathan, do you have an archive of your past WIPs on your personal computer? Sadly some of your WIPs (I'm sure that this has been mentioned before) seem to have not made it to the new format BFC :(
 
Just curious if the MC orders were getting ready or started to get milled? From what I can figure the BC and CC's are all done; does that mean the "big" machines are freed up for the MC's?

Can't wait to get my mitts on this....
 
never.truly.lost said:
Just curious if the MC orders were getting ready or started to get milled? From what I can figure the BC and CC's are all done; does that mean the "big" machines are freed up for the MC's?

Can't wait to get my mitts on this....
Click to expand...

We are finishing up a run of Field Knives now.

The MC HDMC material is here. We have slit it, decked it to width and are in the process of grinding it to thickness. It will start on the Romi for holes and skeletonize in about a week. It will start on the Mori for beveling in about two weeks. This will run continuously across three machines (grinder, Romi, Mori) for about three months. We'll probably put some on the Kia for trim out to get the first started in heat treat before beveling is complete but I don't see anything shipping before summer.
 
Casinostocks said:
Nathan, I'm assuming that burlap handle scales will be offered as an option for the FK2 since we've seen them on the guinea pig protos. Will you be offering burlap as an option with the EDC3?
Click to expand...

No plans for that at the moment
 
Nathan will handle scales from a Light Chopper fit on the prototype Heavy Chopper? I hold the blades that you make in the highest regard, thank you in advance for time.
 
Matthew W. said:
Nathan will handle scales from a Light Chopper fit on the prototype Heavy Chopper? I hold the blades that you make in the highest regard, thank you in advance for time.
Click to expand...
Yes I think so. the shapes are different but the bolt holes line up and I think the profile is pretty close.
 
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