Thanks for clarifying, I would love for all the members here be able to recognize potential problems in a knife upon close inspection, maybe even at a glance. Grind issues and even bent blades can be hidden in pictures, but not easily in person. Bent blades have absolutely no excuse, if the blade is not straight, that happened at the time of heat treating and should have been rectified then, they don't warp after just sitting there, especially after tempering. I have had blades warp in heat treat and I fixed them, sometimes warping badly enough that I am required to go through the whole process again. Most of the knives you guys use are so hard that it requires a great deal of force to bend them on purpose, let alone by accident. Some of the knives with softer cladding may be a little more subject to bending or taking a set, but it still takes a lot of force and determination to do.
Twisted blades are more often than not a result of uneven grinding, especially in full flat or full ground, but slightly convexed blades where it is harder to see than on a partially ground blade. It is easy for a person who is strongly right-handed to grind knives with a slight twist to them, especially at the tip. In this way many left-handers have an advantage, because in our right-hand dominant society, they are forced to use their right hands more. I long ago learned this lesson and grind almost as well left-handed as right. I can't swing a hammer as well with my left, but I do grind with both.
Even grinding comes only with practice, there is no other way, you practice until it is correct. I was surprised when Dave first broached the subject of the overgrinds as you have come to know them. They are present in the larger knifemaking community, and are most freqent among new grinders. I was amazed to hear of this occuring in kitchen knives.
Grinding a knife to thin I have already addressed in my subforum.
Specific questions are always welcome.
I am speechless(well almost) I have no idea why that should be. Its never happened to me. It should not happen at all, I'll have to think about this. I may PM you later about that subject.
obviously with clad single bevel knives, its different, but with clad double bevel knives, it can often be because the thickness of the cladding is different on each side and causes warping (especially when the steel has not been allowed to rest... whatever that process is called where the internal forces are "tempered" so to speak)
single steel knives are often a result of the steel being improperly heat treated in my experience, so if your heat treat is good, i guess you wont see it too often.
With all due respect(which is certainly a lot) to Japan, I have heard tell that traditional Japanese smiths often are not taught to fully understand and respect the annealing process, it's more a heuristic kind of thing, and leads to incomplete or uneven heat treats being more common(though many smiths don't let it past their QC). I've seen pictures of shops that have literally hundreds of knives that rest for months before sale because the steel is still shifting and settling, and late warpage is common enough to warrant the wait.
as far as the "no excuse for the bent blade" thing, does the maker forget to check the straightness of the blade? or is it due to just lack of attention and/or care? I also heard that clad combo steels can warp by just sitting there for awhile, which is why I only get single steel blades now. No experience myself, but I don't want to take any chances with finding about it later in the future. Is it a given for them to warp? or is it the unlucky few who come across this?