Newt Livesay:
<font face="Verdana, Arial" size="2">ANY CARBON OR TOOL STEEL WHEN HARDENED IS STRONGER THAN WHEN IT WAS ANNEALED, AND WOULD BECOME MORE BRITTLE THAN WHEN LEFT SOFT!</font>
This was the point. The relationship between strength and toughness is not as Ben implied proportional but in fact the opposite in that as you increase one you tend to decrease the other. There are exceptions to this of course, such as temper embrittlement which can cause temper that lower the hardness to lower the toughness, but once you get outside of that temperature range the general rule again comes into effect.
As for it being the most common, as I said above, I don't doubt it is. In reference to knives, it is probably the most commonly used however only in cheap blades. Most of the high eng blades both custom and semi-production small shop (Reeves, McClung, Busse Combat), use high alloy tool steels. The only place where 1095 is commonly used in high end blades is in custom forged bowies and the like, and it is common for it to be regards as an upgrade to use 5160 and 52100 for either a large or small blade respectively.
In regards to the toughness of shovels and other high impact tools. The heat treatment of the 1095 in those tools is drastically different than the blades that you produce. It is very misleading and borders on pure hype to imply that there is any similarity between 1095 uniformly spring tempered to 46-50 RC to its performance in the RC range that you use for your blades.
As for my hands on information with heat treating, I would estimate that I have spent about 100 hours heating treating steel. But I would clearly state this is roughly doing only very basic things. I don't have much desire to explore the subject in detail as it is very well known and I can simply as someone who has put the hours in, which I have both with many custom makers as well as people outside the knife industry who are very experienced in such areas. I have been fortunate to have conversed with a number of makers who have provided me with references to the materials technical information that they have used to form the working basis that they have expanded on which has been very helpful as well.
With Cryo, there are many makers who feel the same and many who do not. I am getting two identical blades made with and without and asking the maker to leave them unmarked to see if I can tell the difference between them. Possibly D2 because this is the steel that is commonly used as an example and often claimed to be given very high advantages because of cryo, as you noted, multiple hundred percent.
<font face="Verdana, Arial" size="2">Heat treating of 1095 or any tool steel is not some ?easy process</font>
Relative to the more complex steels 1095 is much easier to handle you must define some standard. For example difference of the length of soak time that who blow the grain size of M2 can easily be handled by 1095. There is also the gain in performance of multiple tempers that comes with high allow steels that isn't nearly as dramatic as 1095.
As for its wear resistance and difficult to machine being similar to D2, well is that is your experience then it is what it is, you are however the only person I have seen claim that for 1095. Then again is your responce to Jim, you basically confirmed the comments that I made in the first place which was that 1095 has a much lower wear resistance (and thus edge holding) than the high alloy tool steels like A2 and D2, and as well they will cut more aggressively.
In regards to the comment about blanking and the grain, this is the exact opposite information you will see promoted by forgers who will say that the best way for blades is to get the grain aligned along the edge. Both of these approaches are again contradicted by makers who state that when the heat treat is done on these materials, the grain is completely reformed and thus the initial conditions don't matter.
<font face="Verdana, Arial" size="2">Someone sent it to me on an e-mail about you comparing a chopping hatchet?s cutting ability against a large knife. I think you said you noticed that the axe cut better?</font>
That was one part of the review, and the conclusion was basically the opposite. As I was working on small wood, 2x4 sized up to I think small trees, 3-4". The purpose in any case was not to determine which one chops "better", (or in general does anything "better"), as that is way to loose a term and something that you can usually just guess from spec's. But to examine how the size of the wood effects the performance of each so to estimate the gain in performance that you would get out of the hatchet as the wood got large and out of the knife as the wood got smaller. The critical point for the wood size is about 3" or basically the width of the hatchet face. As you go significantly under this a decent bowie will readily pull ahead and as you go above it a decent hatchet will readily outperform the bowie. How much of each case I have not as of yet determined as I simply don't have the work done yet. Feel free to provide me with estimates if you have.
-Cliff
[This message has been edited by Cliff Stamp (edited 03-14-2001).]
