Phil Wilson said:
90v does everything 60v did and then some.
Yes, I can understand that, for a knifemaker as well you also have to make knives to sell so you can't afford the time of course to examine every single alloy in detail. I just think that approach to S60V which a lot of people ended up taking by dropping the hardness down to 55 HRC to make it suitable for tacticals and hard use in general is problematic and comes from the wrong viewpoint of trying to make a steel do something which is far outside its optimal range.
Even though the wear resistance is still high at low hardness, of what value is this in knife edges about 0.3-0.5 micron's wide when sharp, if it deflects and rolls even to a micron or so it makes a massive change in sharpness with little to no wear taking place at all, so hardness is really important, which you know already, but a lot of people don't share that viewpoint and those knives were made and a lot of users complained when all of a sudden they had "super steels" which were rolling and denting very easily.
Crompal said:
If you look at machining and grinding as two different operations. S30V may offer more resistance to grinding than will D2 or M2 since it has a higher carbide volume than does M2 and much harder carbides at similar volume to D2. As far as machining is concerned the reduction in carbide size from roughly 30-50 microns to 2-4 microns make the material easier to machine since the tool can scoop out the smaller carbides instead of trying to cut the larger carbides in half which will dull the tool edge.
Yes, not many people in the knife industry make those distinctions, Mission does as Beta-Ti is ground poorly in general but machines easily, on a belt sander it heats up fast but you can file it rapidly. Crucible only discusses machinability in the spec sheets and promotes it as high for the reason you noted which then tends to give the wrong impression if the grindability is significantly lower.
Before you comment on what the material was supposed to be ...
Crucible promoted it broad spectrum, the data sheet specifically states its toughness makes it "especially good for bigger blades", so this does compete with INFI and other steels as that is what they are used for, and it is used for exactly those types of blades. Now obviously Crucible has no responsibility for what makers do with the steel, but where is the information from Crucible saying it should not be used for those applications and is sub-optimal, if anything, the data sheet promotes it.
In general though I was speaking more of the common perception as steels can be judged harshly for properties which don't matter in many applications. I have lots of knives which have very low charpy values (M2 at 65 HRC), but if I am only cutting with them and not subjecting them to impacts of what use is a high impact value, I would rather have a higher tensile/compressional/torsional yield/ultimate fail points, which I do have on those knives and they work very well.
What I would like to see more of is makers like Wilson who has a family of steels to work from as all are quality for various applications and not every blade for every person needs to be the same, and not ever steel is a "quality" choice for every blade, but just do some reading and you will find that use of the label which is itself misleading, similar to saying something has good "edge retention", this depends on what is being cut and how.
From a materials perspective, how do you feel about the japanese trend away from vanadium, and alloys like ZDP-189. The high vanadium alloys have been critized harshly by a japanese metallurgist on the forums. Have you contrasted the high vanadium approach with theirs and found it to be superior? Have you examined the work of Roman Landes who has harsly critized the use of steels like S60V for knives due to primary carbides interfering with sharpness and edge retention.
-Cliff
some just take a long time to work