Thread: Video: How Much Steel Hardness Affect Honing ?

The last video is non existent. First I'd like to comment on "swedish steel", over the last 200 years or so there have been so many steel manufacturers in sweden its not even funny. And they have made so many different steels its impossible to classify a steel as just swedish steel imo. It could be anything from 1095-ish to o1-ish to any tool steel or any strip steel or band saw steel. Its like saying you have an american car. Oh really, which one? An american one...

Pretty much all abrasives are harder than martensite, since martensite tops out at 64hrc or about 1000HV or so, and if you add more carbon to the mix oversaturating the steel you get more hardess but not from the actual martensite/the matrix but now from carbides and cementite I suppose . If you add alloying elements that have an affinity for carbon you get carbides that are much more abrasion resistant (harder) than iron-carbon itself. Most if not all carbides found in steel is harder than aluminum oxide, which I think it tops out at about half the hardness of tungsten carbide for example (or even lower). Even chromium carbide is harder than the alu oxide iirc.

If you put lets say more than 0,5% tungsten in the steel you will get hard carbides, up to that point it acts more like a grain refiner, another common grain refiner is vanadium, and if you put in more than like 0,1% of that you get lots of hard carbides. In the US they prefer to put vanadium in steel since they have lots of that type of ore, in japan they have tungsten rich ore so they use that.

The most problematic steels to grind are the ones with several % of either V or W, since now you have a fine grained steel, with lots of finely distributed carbides that you can't cut even with silicon carbide, and the carbides reside at the grain boundaries, so your only hope is to abrade the steel matrix supporting them until they simply fall out. It gets worse if you temper these steels at hss temperatures since there are 2 different carbides formed in the steel (primary and secondary ones), and the one produced after a high temp tempering are harder to grind, but the matrix gets softer though... and hardness of the matrix is directly equivalent to strength.

If you're unlucky you can have the worst of two worlds all in one single piece of steel Impossible to grind large multimetal carbides suspended in a weak but tough matrix.

About 10 years or so ago a steel called s30v showed up, full of V (4%) Mo (2%) and 1.45% C, total nightmare to grind/sharpen if hardened to its full potential. Unless you have diamonds. Usually you can't even polish it well.

If you want easy to hone steels, avoid everything with W or V in it. Especially when the description of the steel is so vague as it is with razors. Thats my recommendation.