Lets get some discussion going on the pros and cons of certain blade materials we would consider high performance.

How about Talonite first...pros...cons...comments?

Craig

Not exactly Talonite but on the same line Stellite 6K.

Stellite 6K is a coarse grained material which will not mirror polish but will give a high lustre finish, I prefer to call it semi gloss.

Grinding is not unlike other knife steels but because of the hardness stock removal is a lot slower. This is not a bad thing, it gives you time to think and to finess the grind a lot.
This is necessary considering that you cannot use a file to dress up corners and such. I use aluminum oxide belts with no problems, one belt per blade, not bad considering value of blade to value of belt ratio.

Drilling is done with carbide drills or not at all.

Filework with a carbide dremmel tool cleaned up with diamond dremmel bits is as easy as working with hardened steel.

The total stain proof nature of the material allows etching of bolsters directly on the blade without damaging the blade, this allows use of etched Damasteel bolsters. I have etched in both ferric chloride and muriatic acid with no blade damage.

Sharpening is easy on the wheel or with diamond stones.

I don't know anything about working with Cobalt alloys, but I carry a Mayo TNT everyday, and it is a wonderful blade for most anything you need to do. I abuse the hell out of mine, have dinged the edge in a couple places, and it keeps on cutting.

Tom puts a wide convex edge on his blades, same as I do on mine, and it works well with this material. The convex edge lets you use a bit steeper edge angle to get the same cutting efficiency, so it helps protect the softer metal from damage.

Interesting comments about Stellite. I have a few questions:

It is my understanding that these alloys are basically hard carbides suspended in a cobalt-chromium matrix. Now, I have heard that the basic matrix is relatively soft and that Rockwell penetration tests guage the hardness in the 40's (HRC).

If that is so, why is it so hard to drill and machine? Is it true that it cannot be filed, or do I misread that?

Thank you.

If you think about, the carbides in the matrix will grind away the steel in a drill bit. In other words the material you're trying to cut, cuts back.

Jerry is right about the carbides...they are there in the form of large crystals, large enough to see with the naked eye when you try to mirror polish the blade. Having chunks of tungsten, vanadium and molybdenum carbide in a soft matrix complicates the drilling etc considerably.

I am working on several Talonite knives right now. Because I am to cheap to buy a letter "F" carbide bit, I drilled a 1/4" thong tube hole in them and will turn the thong tubes down a couple thousandths in the lathe. I won't even think about using an HSS or cobalt bit- they just won't "cut it." ;)

One real plus (as opposed to the often-repeated negatives) to working with these materials is that I can totally skip the heat treating. That tends to make up for time lost in slow grinding and finishing.

Another downside is cost. Each of these blades contains about $100 in blade material, making it as pricey as damascus.

As Jerry noted, though, it's all about performance. It cuts. And cuts. And cuts.

Not having to HT or cleanup after HT is certainly nice. Tapering tangs, at least by my method, is a chore because this material doesn't stick to my magnet. I don't really care for the 'graininess' of the finished blade, either. Oh, and the is exceedingly high, IMO. I only use it by customer request.

Brett

OK, what about S30V??? I realize that this is a very new steel and maybe Jerry is the only one that frequents the forums that has used it but any comments???

Craig

I may be able to talk rationally about S30V is about a week. I'm right in the middle of grinding 32 blades in it, including 2 swords, 5 bolos and some other big knives, so I'm really really not happy about it. It is miserable stuff to work!!!!

hey........you guys suck!!!! :) :) :)

Hey, who let you in here? Go away!!! :D

He must be feeling better!!! :)

f you think about, the carbides in the matrix will grind away the steel in a drill bit. In other words the material you're trying to cut, cuts back.

actually....if you try to drill stellite with a cobalt bit, a new one...it initially cuts a little, gets dull, then gets red, then starts smoking, gets cancer, and dies....with little or no effect on the stellite.....

trust me.......I know!! :)

you cant get rid of me.......I part of the TEAM!!!!!!!!!!!!!!!!!!!!!!!
besides....Im an ELITE MEMBER!!! :) :) :)

Tom forgot the last part where the drill bit stops turning and refuses to be removed from the hole.

I use carbide now.......never have that problem.....I only tried the other way once.............how about you?

What about BG-42? Is it hard to drill and grind? what about milling a blood groove in it? ATS isn't fun to mill.

If you use the right abrasive or tool bit material for the job, none of the available blade materials poses any great difficulty, IMO. Stellite and Talonite drill easily with carbide drills, either spade or straight flute, and grind fine with caramic belts at moderate speed.
The more wear resistant alloys (S30V, 3V, 10V, 15V, S90V) are difficult to obtain a fine finish on, due to their wear resistance. (Vanadium content)
If you want a fine, "collector type" finish, I'd suggest BG42-It finishes beautifully, right down to a mirror finish.

RJ Martin

I haven't used S30V much, but I already have one major complaint. It heats up much too quickly. S90V is a pain to finish, but it's very resistent to heat buildup.

Brett

S30V likes to be ground at lower speed. It's not so much a heating problem; it just loads the belt less. I've not had any problems with it getting hot, but it is fussy with the belts that work best.

Thanks, Jerry. I'll give that a try. It's kind of funny, I actually increased the speed over what I normally use. I suppose I was anticipating something more similar to the hard grinding CPM steels.

Brett

I use 3M #967, 40 grit, for rough grinding S30V. They like to run slower. The steel ate #977's. No question though, it is very gummy stuff and loads up belts in a hurry.

I used the Norton belts on it, and they worked great! and the Norax's. I did 2 kitchen knives, full flat grind on the contact wheel and it worked really well. I am also working on some normal flat grind pieces.

Well, I discovered my problem. I was trying out some Zirconia belts (just to satisfy my curiousity) and, while they seemed to remain sharp, they weren't cutting the steel very well. Back to the 967's and 977's. Thanks for the input.

Brett