the two blades i used for the pictures are a super cheap set of throwers, i assume made of 420, wich can be bent (very very easily) in the hands. they are butter soft. the second (the chipped blade) is a blade that I'll leave unnamed (you can figure it out if your willing to search for the original post), wich is made of 5160. the hardness is unknown, but its definitely hard.
1: edge dent.
an edge dent is where something hits the edge at an angle, and moves a small section of the edge to the right or left, misaligning that portion. no metal is removed in this action, and it can be steeled or burnished out, basically bumping it back into alignment. an edge dent can be very very small, to a degree that its difficult to see whether or not the edge has been pushed over, or it can be shoved so hard and so far that the metal actually tears along the center line of the dent.
2: an edge mash.
an edge mash is when you hit something dead on, like a piece of metal or a rock, that causes the metal to push into itself, mushrooming out the sides. this can be pushed back into form with steeling, though this is harder to do then with a dent. no metal is removed in this deformation. in the case of this cheap thower - the mash is bad enough that it actually split the metal that was mushroomed out. this stuff is really, really, REALLY soft. to cause this mash i hit the edge on the back of another knife. this is a good example of what I mentioned above, where if your steel is the type that is very resistant to fracturing and chipping, a deformation of this magnitude will tend to split the steel once it deforms to a high enough degree. mashes like this can be very deceiving - sometimes they look very convincingly like chips. unlike a chip however, a mashed edge will always mushroom out to the sides, you can tell this by running your fingernail along the edges of the deformed area. if you find that the metal has deformed to be rounded around the deformed area, chances are the the metal has simply mashed down, rather then suffered a fracture.
3: rolled edge.
this is where your slicing something, and you run a length of the blade across a hard object, like a metal wire, a nail, or a rock. it causes what is essentially an edge dent, but over a long area of the edge. again, no metal is removed in this deformation, and it can be steeled out.
4: edge chip
this is the type of damage that jerry says he has never seen occur in one of his production infi blades. this is where you hit your edge on something hard, and it actually cracks out a piece of the blade. when this happens, there is actually a chunk of metal missing from the edge, which can cause an area that is prone to cracking in the rest of the blade if its bad enough. the only way to fix this type of damage is to sharpen the geometry of the edge/blade past the missing metal. in differentially heat treated blades, the chip can sometimes be so bad that it goes past the hardened portion of the edge and goes into the softer spine area of the knife.
infi will have the tendency to do one of the previous three forms of deformation. this is do to a high degree of plasticity at high hardness. its a similar effect to whats seen in softer steels, but it takes much more force and stress to effect the deformations due to infi's high hardness.
there are 2 basic ways to differentiate a chip from the above types of damages.
1: a chip will not be deformed around the edges, or at least not around the entire area of the damage. it may be bent at one side, but the other side of it will be a clean perfect edge with no mashing or smoothing of the metal - it will have fractured away from the knife as though it were a chip of glass.
2: where steel chips away from its matrix - the visible grain of the knife is present. normally when steel is mashed or moved around by another object, the area of deformation is smoothed out by the pressure and friction of the object. when an area of steel is chipped away, you are uncovering the inner portion of the steel that has not been touched by the object that caused the damage. you will be able to see a rough surface in the missing area of steel.
chips are caused by the steels inability to compound or become plastic, or to change shape, like plado. when there is a line of molecules that are unable to adhere to each other under a given pressure, and they are very rigid in their structures, they will tend to break and fracture along that line (grain line). if the adhesion is strong enough, and the matrix is able to plastisize, the steel will tend to deform before fracturing. If the steel is soft enough, or has a high enough ability to plastisize, it will be more likely to tear then it will be to fracture. I could not chip the throwing knives used in these pictures. they are simply to soft, I could cut them, bend them and tear them - but it is not possible for them to chip under normal use. their ability to become plastic is simply to high.
infi Is not quite that plastic, but it is to a degree that it is essentially impossible to chip it's edge under normal use (which is to say without creating a making designed to force it to chip, such as a high speed hydrolic hammer angled to achieve a desired effect). infi is heat treated and designed to stay plastic at high hardness (59-62rc), and as a result, it will never chip. if it ever does, I will be very, very amazed - and will first have to ask wether or not the blade was tampered with regarding its heat treatment (torch taken to it, dremel, high temp oven etc).
