Cliff Stamp
BANNED
- Joined
- Oct 5, 1998
- Messages
- 17,562
Gabe, a couple of years ago I checked out a huge number of materials books and looked for properties of steels, what I found was that you could get large deviations among properties from one reference to the other. Many of them also come from the steel manufacturer which is of course hardly unbiased. The ratio I quoted is from Bryson's book on Tool Steels, it is the one I think is most accurate based on my experience with A2 (Reeves and
Mission).
Bailey Bradshaw :
Abuse of what kind, assuming you are hardening 3V to ~58 which is where its impact toughness peaks according to crucible, then I would expect you to see a lot of deformation with 5160 since you are running it at 53 HRC. It should certainly be fairly flexible at that hardness and thus I would assume the edge is quite resistance to fracture.
Toughness is how much energy it takes to induce fracture, ductility or malleablity is how much a steel will bend before it rips, these are known materials terms just like hardness. In determing these points you have to exceed them. This is why I don't pay attention to claims like "I have never seen a XXX blade roll or chip", it means the maker not only never determined the failing point, they never studied the way in which it fails which can be quite smooth, or very dramatic and totalitarian.
You would expect this if you are leaving them 4-5 HRC points softer.
Anyway if you are getting better toughness in your 3V blades vs other spring or high impact tool steels the first thing I would question is how do your your 3V blades compare to those steels (L6, A8, 5160, etc.) by *other* makers, as it is rare to see those steels detracted for durability reasons.
In any case this is one of the first if not the first time I have seen a maker promoting the toughness of 3V over traditional spring and high impact tool steels which is interesting. It would be worthwhile to see some specifics on the kind of work done to examine edge durability, where did the 5160 and L6, etc. steels fail to peform and then questions can be asked such as have other makers been able pass those tests with those steels.
I can give you 100 3V blades with horrible performance, would this then be an effective arguement that it is a poor steel if you have seen just one that didn't.
Depending on just how small a scale you want to look there are a jillion variable in any comparison, however you only consider the ones which are of relevant scale. A spring tempered spine increases the impact toughness and ductility of a blade massively, unless you want to argue that 3V at full hardness is tougher or more ductile than a spring tempered spring steel which is kind of extreme. Now there is still the edge comparion of course.
These tests in general are kind of meaningless because you would not ever actually do that if prying with a blade because the danger level is too high when the blade goes much past even 20-30 degrees, plus the torque disadvantage is scuttled once you drop well below parallel so you are achieving very little for a lot of effort. Now you could argue that it is a test for ductility and therefore can be used to predict edge damage in extreme cases, but this is usually not the case because the bends are achieved with the help of extreme distal tapers, as well as highly artifical senarios like bending around molds in the vice.
You can get extreme flexibility with distal tapers and thin stock. For example I had two Ontario machetes which were that brittle they exploded on cutting hardwoods (quarter zied chunks), yet even with the pieces missing they could be bent to far past 90 degrees, the longer one could take the handle almost bent to touch off the blade and I had scored it deeply with a Dremel and when broke would show little bend and thus indicating near zero ductility inspite of a huge flex. I have seen similar performance with lots of other blades and thus I am not impressed with large flexes.
Now if you can get large bends against square vice jaws with far from optimal geometries (thick sabre ground blades from heavy stock with no taper), with a large permanent bend before breaking it would be an indication of a fairly ductile steel. You would also want a large spring back and heavy resistance during the bend at the same time to get a balanced blades as otherwise for example you could get maximum peformance by leaving it annealed.
-Cliff
Mission).
Bailey Bradshaw :
Abuse of what kind, assuming you are hardening 3V to ~58 which is where its impact toughness peaks according to crucible, then I would expect you to see a lot of deformation with 5160 since you are running it at 53 HRC. It should certainly be fairly flexible at that hardness and thus I would assume the edge is quite resistance to fracture.
Toughness is how much energy it takes to induce fracture, ductility or malleablity is how much a steel will bend before it rips, these are known materials terms just like hardness. In determing these points you have to exceed them. This is why I don't pay attention to claims like "I have never seen a XXX blade roll or chip", it means the maker not only never determined the failing point, they never studied the way in which it fails which can be quite smooth, or very dramatic and totalitarian.
You would expect this if you are leaving them 4-5 HRC points softer.
Anyway if you are getting better toughness in your 3V blades vs other spring or high impact tool steels the first thing I would question is how do your your 3V blades compare to those steels (L6, A8, 5160, etc.) by *other* makers, as it is rare to see those steels detracted for durability reasons.
In any case this is one of the first if not the first time I have seen a maker promoting the toughness of 3V over traditional spring and high impact tool steels which is interesting. It would be worthwhile to see some specifics on the kind of work done to examine edge durability, where did the 5160 and L6, etc. steels fail to peform and then questions can be asked such as have other makers been able pass those tests with those steels.
I can give you 100 3V blades with horrible performance, would this then be an effective arguement that it is a poor steel if you have seen just one that didn't.
Depending on just how small a scale you want to look there are a jillion variable in any comparison, however you only consider the ones which are of relevant scale. A spring tempered spine increases the impact toughness and ductility of a blade massively, unless you want to argue that 3V at full hardness is tougher or more ductile than a spring tempered spring steel which is kind of extreme. Now there is still the edge comparion of course.
These tests in general are kind of meaningless because you would not ever actually do that if prying with a blade because the danger level is too high when the blade goes much past even 20-30 degrees, plus the torque disadvantage is scuttled once you drop well below parallel so you are achieving very little for a lot of effort. Now you could argue that it is a test for ductility and therefore can be used to predict edge damage in extreme cases, but this is usually not the case because the bends are achieved with the help of extreme distal tapers, as well as highly artifical senarios like bending around molds in the vice.
You can get extreme flexibility with distal tapers and thin stock. For example I had two Ontario machetes which were that brittle they exploded on cutting hardwoods (quarter zied chunks), yet even with the pieces missing they could be bent to far past 90 degrees, the longer one could take the handle almost bent to touch off the blade and I had scored it deeply with a Dremel and when broke would show little bend and thus indicating near zero ductility inspite of a huge flex. I have seen similar performance with lots of other blades and thus I am not impressed with large flexes.
Now if you can get large bends against square vice jaws with far from optimal geometries (thick sabre ground blades from heavy stock with no taper), with a large permanent bend before breaking it would be an indication of a fairly ductile steel. You would also want a large spring back and heavy resistance during the bend at the same time to get a balanced blades as otherwise for example you could get maximum peformance by leaving it annealed.
-Cliff
I had a pic of a fancified version with damascus / snakewood / gold inlay, but can't seem to find it.
