What is 8670 steel, How good are John Greco's

B

backpacker

Joined
Oct 2, 2000
Messages
201
I noticed that John Greco uses 8670 steel. Can you tell me how good this steel is and how good are John Greco's knives?

Thanks for your help.
 
All I know is that 8670 is a high carbon, non-stainless tool steel. I have no idea how good a knife steel it is. I have had no experience with Greco knives.
 
i have a greco tanto 5.5", a good knife, sheath isnt the greatest for concealment, but a good, heavy duty, industrial strenghth knife imho, well worth the $$

greg
 
Ok, I dont know much about this steel either, but I have done a little grinding on a Greco knife or two. Usually, the Greco knives come a little too thick for my tastes, so I end up reprofiling them. The first couple Grecos I reprofiled were A2, but the last one was 8670. I dont know how hard Greco gets his A2 blades, but it seemed to me that the 8670 blade was a little harder to do any grinding on. I took the handles off one of those $50 specials and have done some thinning and reprofiling. Should be interesting once it is done. 8670 seems to be a pretty good, wear resistant steel.
 
As tallwingedgoat says, 8670 is nickle bearing. I have run across it refered to as a saw blade steel much like L6. My experience with L6 is that it is harder to sharpen than some alloys. It seems ductile and inclined to form a wire edge. I spend extra time in my finishing steps when I sharpen my saw blade knife. I do some extra burr removal steps. I would expect the blade to be particularly tough and hard to break.
 
I spoke to Mr. G. last spring ref: 8670 steel. It seems his is German in manufacture, and used to cut the slots in case hardened screws. Believe me when I say I,m no steel expert,that's why i went to the man.
 
I am no 'expert' either- for that ask in Shoptalk.
However, this much anyone can find in a book- according to UNS (Unified # system) first # refers to primary alloying element(s), 2nd is rough percentage of this element(s) in over all steel content, 3rd-5th # roughly equals fraction of 1% carbon content. With this, 8670 means :
8 ="nickel, chromium, and molybdenum "(according to UNS listing)
7 = these alloying elements amount to roughly 7% of steel content (6.5-7.4%)
70 = 0.70% carbon in steel content

For comparison, in UNS classification "5" in 5160 and 52100 means their primary alloying element is chromium, in 5160 it is roughly 1% and it also has approximately 0.60% carbon content, in 52100 = approx 2% chromium and 1.00% carbon content.
But #s for 8670 suggest it is like L6 as said in previous comment, however the difference is higher chromium content, in L6 it is 0.03-0.75% and in 8670 educated guess is approxmately 3-3.25%. (I don't know "L6 ' means, it derives from different classification system)
Again, this is just book information, you can find it in any book or source with UNS listing. It is also on the internet, perhaps someone can provide a link.
Martin
 
Just to make this even more fun :p

Howard Clark says L6 should be renamed 4370, as it's basically 4340 with more carbon. For those into rifles, 4340 is the top quality barrel steel.
 
I have one in A2 (a green River companion as shown at blade art) and have four in the mail in 8670. I met John Greco in January, very nice guy. His knives are well made, and a real bargain. They are thicker than I would like at 3/16" ( I generally prefer 1/8" or 5/32" stock), his hollow grinds are fairly deep (Personally I would like them deeper and higher) and the edges are ground rather thick, but at a high polish and a very high level of alignment. In sum, Greco builds his knife primarily for strength, but they also offer good cutting performance. They will not slice like a Sebbie or TTKK but Greco knives are certainly strong enough to handle any reasonable task.


Chad
 
The 86xx series low alloy steels evolved from the National Emergancy steels which were developed during WWII to conserve nickel and other alloying elements.
The nominal alloys in the 86xx series are 0.55% Ni, 0.50% Cr, and 0.20% Mo.
L6 is a low alloy tool steel with 0.70% C, 1.50% Ni, 0.75% Cr, and 0.25% Mo.
The 43xx series (1.80% Ni, 0.50 or 0.80% Cr, and 0.25% Mo) is closer to L6 than the 86xx series.
 
John Greco is a first-class man to deal with. Another one of the "good guys" of this industry.

Hope that doesn't start some type of pissing contest on this thread :D
 
His "production" knives are a little thick in the edge - may not be the case for the new "Lile" line. His true custom work is first class.
 
I own a Greco Companion, and have just ordered one of the new Greco-Lile models. The Companion is made from 1/4 inch stock, and I have found it too heavy and ungainly to use for every day household chores. I am not sure what sort of use the older Companion would be good for - self defense, maybe ?

I would not have ordered another Greco, but the new line is made from thinner stock. I am hoping excessive weight will not be a problem with the new one.
 
You must log in or register to reply here.
Back
Top