golok :
There are knives that have an above average thickness blade. Is this really necessary.
Thickness gives strength, thus if you want to be able to pry forcefully you need a decent thickness. About 1/4" of fully hardened steel, with a v-grind, has a breakpoint of in the region of 3000 in.lbs of torque, which is enough short of two handed deadlift type movements, or jumping on the blade, or prying with the very tip. However if you want to be able to do any of those things you will need more thickness. You can just use a more obtuse primary grind, but that lowers the cutting ability, and you don't need to do that with thicker blade stock as you just make the blade wider. So basically the thicker blade (and wider) allows a higher cutting ability at the same strength as the more obtuse primary grinds on the thinner blade.
As well, if the blade has a selective hardening (softer spine), it will be much weaker than a fully hardened blade and thus you need more thickness at the spine to raise the strength up to the same level as a fully hardened blade. This is why traditional khukuris for example only go down to ~3/8" at a minimum as they would be far too easy to bend at 1/4" thick as they only harden very close to the edge. The spine on those blades is left very soft to take the serious pounding that they sometimes have to endure. So very basically, the thickness allows a much higher impact toughness at the same strength. Even with the very thick spines (sometimes approaching 3/4"), they still cut very well because they are wide enough so that the grinds are decently acute.
Now the argument could be made that with modern materials you can shave off some stock. Well yes you can do this with toughness, however not so much with strength and because strength falls off so rapidly with thickness (quadratic), you can't go much below 1/4" anyway or it becomes far too easy to bend. Easy of course is a relative term, but to put it simply, someone who wants the strength of 1/4" thickness in 1095, isn't going to be satisfied with 3/16" CPM-3V. Even though 3V will have a small strength advantage, it isn't as large as the thickness change will induce. However toughness is another matter, the difference in impact toughness can easily be that much that a really tough blade at 3/16" (5160 at ~58 RC) will easily outlast a brittle one at 1/4" (D2 at 62 RC) when both are subjected to high impact pounding.
There are also a number of advantages that thicker blades make for actual functional cutting. For chopping for example they bind less and thus allow a more fluid pace. They are heavier and thus make better hammers and impact tools, the wider spines also do the same thing by giving you a larger impact area. The spines are thicker and thus are more comfortable for control as when using the blade as a drawknife.
MJHKNIVES :
... the last time I ground a stainless blade. I thought, better leave it real thick, because i'm using this weak sub standard material. Hogwash.
Stainless steels are not weak, in general they are very strong especially compared to the low allow steels. However they are much more brittle than the non-stainless steels, especially the plain carbon steels (1084), the spring steels (5160), the high impact tool steels (A8), of course the shock steels (S7), as well as the general purpose steels like 52100 and L6. This difference is on the order of many to one, not a few percent.
Less distal taper in SS knives is just the nature of grinding your blades VS, forging.
You can get extreme distal tapers on stock removal blades, Phil Wilson's hunters and fillet blades for example. Any fillet blade would do as an example, even the cheap production ones taper strongly from 1/8" to under 1/32" .
Ed Caffrey :
I personally see no need for a blade to be a specific thickness throughout it's length.
To maintain an overall high level of strength, as while distal tapers allow a very high level of flexibility they also weaken blades significantly. As well to leave the tip strong and durable for high impact and prying work. Also to leave enough thickness than it doesn't bind excessively when chopping. Of course, a strong distal taper does have advantages as well, just as any choice you make with a knife, steel or geometry wise there are positive and negative aspects. As to the right or wrong nature, this can only be judged once you know the intention of the design.
-Cliff
Hogwash. Less distal taper in SS knives is just the nature of grinding your blades VS, forging. No knifemaker is going to use weak sub standard materials in their knives.Not any good ones anyway. Enough of the bs, were all supposed to be craftsmen/artists, and professionals here.