Im interested in steel that can take the sharpest edge, now that would be shirogami 1 white steel? Also is honyaki knives able to get sharper, or will they just maintain their sharpness longer?
Also im quite confused about cladding, does honyaki knives have shirogami cladding? wouldnt carbon steel edge and stainless steel cladding be the best of both world? is there alos some knives refered to as lasers without cladding or something?
If you want to shave, simple fine grained carbon steel like shirogami will give the keenest edge. This may apply to cutting sashimi to an extent.
However if you want to cut food, the difference in sharpness between different carbon steels, many semistainless steels (and perhaps some some stainless steels such as AEBL) is not that relevent. That is to say, all of these steels will get sharper than is useful for general kitchen use (assuming that they are well made and heat treated). I could start an argument by asking wheter people put PM steels in this category. My feeling is that many PM steels produce a pretty good edge for kitchen use which lasts a loooong time.
The reason that ultimate sharpness (technically, we mean keenness rather than sharpness) isn't needed for most kitchen tasks is that kitchen knives actually benefit froma bit of toothiness (microscopic serrations) to the edge. Most people would not sharpen most kitchen knives past 3-8K (depending on the knife, even less for many stainless steels) and most carbon, semistainless (and perhaps some stainless steels) can easily take this level of polish.
Some of the different knife constructions are:
Monosteel: the blade is made of a single steel. Like a Wustoff or a Masamoto KS.
Integral damascus: 2 steels for are forge-twisted together into one mass to form a patterned blade (which is effectively a monosteel).
Honyaki: a monosteel blade where the steel near the spine is made very soft and the steel near the edge is made extra hard. This is called differrential hardening and is often acheieved by coating the spine of the knife in clay before quenching. A pretty pattern or "hamon" line between the two hardness of steels can result. It's pretty hard to do without cracking the blade, so honyaki are often pretty expensive. The benefit of the softer steel is that it increases the overall toughness of the blade which would otherwise be very brittle if the steel is maximally hardened.
Clad (san mai): there are 3 layers of steel. A hard steel is used for the core (cutting edge) and a softer steel (lower carbon) is used to clad the core. This increases the overall toughness of the blade and also makes it easier to thin the blade. Most stainless and semistainless san mai knives have a stainless cladding. Some carbon knives have stainless cladding, others are clad in "soft iron", or very low carbon (non stainless) steel. Note that the cladding can be made in a damascus (suminagashi) pattern (and this can be done with both stainless and non stainless claddings).