To test two steels and draw some sort of conclusion, won't both knives need to be the same HRC?
That depends on what question you are trying to answer. If you wanted to know which steel was better for a knife you would heat treat each so as to give the optimal combination of properties. This will rarely give them both the same hardness and almost never end up at 60 HRC.
Now as for the both same maker, etc., if the difference in the steels mentioned here were that slight that the only way to see them would be if the same maker made both the exact same knives - what does it say in general for people buying knives and chosing between those steels?
Obviously that the steels do not matter.
The types of comparisons made by Mike in the above are actually more valuable to the buying public because they represent the real differences that will be seen. Few people are going to compare identical knives and thus for advantages of steels to actually MATTER they need to be large enough to overcome that.
Consider a few points :
Lets assume that instead of the steels used the Military was S90V and the Sorg 420HC, what would the result be and what conclusion would be drawn in general? In short, S90V would have a HUGE advantage due to the massive carbide fraction and this would swamp out readily the differences in geometry. Thus the buying public could then infer than if you compared to knives, one in S90V and another in 420HC, even if the knives were different, the S90V blade would tend to have a large advantage in slicing aggression. Note this is exactly the proposition that makers affirm constantly.
How about if instead Mike has done hemp rope cutting as a measure of sharpness and cut to the same force as Goddard does. In this case the 420HC Sorg would cut well ahead of the Military for a long time (it has a much more acute profile). Now what would this mean in general to the buying public? That if you look at cutting ability and not sharpness then the geometry can be far more important than the steel.
Of course Phil compares two blades, and is 100% welcomed for his work (as he should be). Now Mike compares two blades and gets questioned on reaching conclusions because of two blades. Now to expand on the above, if you accept that a=b in Phil's work, then you have to accept b=c in Mike's work which was actually much more quantitative. Thus it follows a=c.
Now again the equals here means "not significantly different" which is a fairly loose statement. it just means no difference was noted that could be proven statistically. It does not mean you proved they were equal, the work just failed to show there was a significant difference. Note that any user will have vastly lower tolerances and thus if careful quantitative work does not show a difference, no user just working will see any.
Again just consider what a normal user would see if they were given all the blades to cut with.
-Cliff
