#1 in progress ... pre-HT

Rob Nelson

Well-Known Member
Aloha,

Here's my #1, D2 blank thanks to RodneyJ. Hand filed and sanded, and tentatively ready for heat treat. Gotta be honest, this feels like one of those projects where you just don't know when to say "done", but the edge is slightly thicker than a dime, so I better stop. Here's some pics. Let me know if you think I should hold off on HT or go ahead. Any suggestions on HT, btw? Any benefit to differential on D2, not so much for a hamon, but spring and edge?

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Plunge line was deeper that expected; used a chainsaw file and it just felt good to make progress :D: Sanded with 60, 100, 150, 220 - went 320 and 400 on the blade just to see. (Paint stick backed by the 10" file worked great as a sanding block). My drill holes aren't quite perfect, but the 3 I'm using for pins and the one I'm using for the tube are straight. Cobalt bits are amazing. I tried to relieve some weight to move the balance closer to the ricasso. It's still tail heavy, but that gives me something work on for the next one.

Thanks ahead for any feedback - I'm a blank slate, here to learn.
 
That plung line really concerns me. How thick it it compared to the blade? If it is much thinner there than the rest of the blade you will have a real weak point there. I would lean towards chalking this one up to experience and starting over. I suggest that you mark the midline of the edge and file to it going no deeper than you want the pre-heat treating edge. Actually, it might be better if you cut the plunge line just slightly thicker than that and bring it down with the rest of the blade when draw filing and, of course, use a filing guide.

You might go ahead and finish the blade for practice, if you want, but keep it for yourself. Maybe do distructive testing with it.

Don't be discouraged. That knife looks much better than my first knife and, to be honest, most of us probably don't make even an acceptable blade the first time out. You are doing good.

Doug
 
Doug, the plunge line is wide on the surface like a triangle whose base is the width of the 5/32" notch. The point starts .425" in from the spine with the blade measuring .137" thick, and tapers down to the notch. At the notch, its .045" thick. It's still at .100" thick .3" in from from the notch and the taper is gradual. The rest of the grind is more convex in comparison to the plunge line which tapers in a flat line from point to base. Does that make sense and does is still sound okay?

Thanks for all the help!
 
I think by your measurements you are OK I think that it stands out in the picture because the rest of the blade is more convex than the plunge.
Rodney
 
Allrighty then, I need to get this puppy heat treated! I'm not certain how this works, so here's a few questions.

- I understand D2 might not be as good for showing hamons, so from that perspective a differential heat treat might not be as important, however doesn't the differential HT preserve spring in the spine, while hardening the edge? Should I seek that for this blade?

- Part of me wants to encourage the other learners on this journey with me, so I'd be just as happy to send it to a hobbyist as to a full time business. What's the best way to connect with one to arrange for heat treat?

... in the meantime, think I'll sketch a few more ideas for future projects!
 
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I'll go with Rodney on this if the grove on the plung line is really not as deep as it appears in the photos. I still think on future knives that you might want to cut the plung line just a shade shallower that you want to cut the bevels prior to hardening and blend the forward part of that line into the bevels when you draw file so there's not as much of a transition. It will look a little better.

D2 is a deep hardening steel and will not form the necessay structures to show a hamon. A soft draw on the spine will reduce the hardness and strength of the steel in the spine and increase the toughness and ductility due to martensite. That's with any steel. However, there are other things that increase hardness, thus being more subject to brittle failure, than an increased tempering of the martinsite. D2 has a lot of carbon and other eliments that will form carbides. I don't have a hardening chart for D2 so I can't say for sure but it may be high enough alloy to have secondary hardening due to carbide formation. What this means is that if you heat the spine up high enough you will actually increase the hardness and accompanying brittleness. Short answere: I wouldn't choose D2 to attempt a soft draw on the spine with unless I could confirm that it does not have a secondary hardening range. It's also not a steel that will pass the 90 degree bend test with a hardened blade.

Doug
 
I don't know how you could differentialy heat treat D-2 since it must be slowly heated to 1900 deg. then held precicely at that temp for 20 min. then air quenched or plate quenched. Temper it at 400 deg. 2 times for 2 hours each, this should yeild a Rc of 59 to 60.
If you are going to finish this up by hand sanding good luck, you will need a 55 gallon drum of elbow grease and a tractor trailor load of sandpaper. If your heat treat goes right and you harden it to 59 or 60 Rockwell the D-2 is so abrasive resistant it will take a LOT of work to hand finish this knife. Use wet dry sandpaper and use Simple Green diluted 4 to 1 instead of water and the sanding will go faster.
I'm not trying to discourage you, go ahead with it and good luck!
 
Doug & Calvin, thanks for the info on D2. Guess I'll get ahold of Brad at Peters then!

I may flatten the convex a little then too before HT if it's going to be that abrasion resistant after HT. Appreciate the encouragement there Calvin :D:
 
Calvin is rihgt, D2 is an air-hardening steel with very high carbon (1.5%) and 11-13% chromium (nearly stainless) that requires a good controlled furnace to HT properly. NOT a good candidate for a hamon or any other differential hardening. Finish it very close to final dimensions and polish now and let a pro heat-treat it. Brad will take good care of you.

If you're looking for steel that be HT'ed in the backyard with some success, and/or ones that respond to differential tempering, stick with simpler alloys like 1084.
 
Chapnelson, just a question. What kind of reference material do you have? These sites are great for gathering information but it's not presented in orderly fasion. If you don't have any books that deal with knifemaking by stock removal, it take it that is the method that you have chosen to use, then you really need to do some reading. How to Make Knives by Richard Barney and Robert Loveless would be good. It looks like Knifemaking Home Workshop by Wally Hayes would be a good video. Both seem to be geared towards stock removal and both can be purchased through Jantz though I would think that Amazon would carry them too.

It's easy to take a little information to a wrong conclusion, especially when you're just starting off. Been there, done that, and have the scares to prove it. You can work with D2 but, as Calvin mentioned, not easily with hand tools. You could get a palm sander and replace the platen on it with a piece of micarta and use it to do the sanding but it might be easier in the future if you choose a simpler steel that is easier to work with after hardening and tempering. It's not hard to build or adapt the equiptment that you need and learn to do the job yourself on simpler steels.

Doug
 
Doug, appreciate the book suggestions. (I make the same sort of suggestion to new reloaders.) I have the $50 knife shop (also thanks to Rodney) but will be adding a couple more!
 
The $50 Knife Shop is probably better for the knifesmith than the grinder. It's also only really good for the person who is just starting out and only needs the very basics but it is wanting in detail. I think that there are better books for both the forger and the grinder. I think that a good reference library is the most important tool a knife maker can have. I've managed to collect a number of books and videos on the subject and I refer to them often.

It's kind of a measure of how badly you're afflicted by knife making by the number of books on the subject you keep by the bed for a little light reading before lights out. I'm long gone.

Doug
 
Update: Brad is going to sandblast it for me, and I should have it soon ... maybe this week! Now I just need the belts from trugrit ...
 
I agree fully with doing your finish sanding before heat treat. I've been using and heat treating D2 for years. It's a snap (very little elbow grease) if you sand to 600 when it's soft, heat treat in Stainless foil. A friend of mine has been in my shop building his first knife and it's coming along fine. Perhaps there's a knife maker near you who will have you over... nothing like hands on training to bypass all the threads.
 
Update: the D2 blade is back, but the belts aren't yet. So I rubbed the scaling off, and went ahead and started on the handle.

Jeff, I haven't linked up with a knifemaker in Oahu, but hope to find one in the Norfolk area when I pcs in a few months ... Lord willing and congress passes a budget.
 
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