Jiri,

I would take the word of The Timken Company over those that you mentioned; however, I would wager that if YOU asked them and they printed it, it would VERY CLOSELY match what Timken said.

The Rockwell "C" scale values they quoted are reasonable for comparitive purposes. Here is a little secret for you, the harder the steel the more brittle it becomes, generally . Both the 440A and 440C are better than 420HC in wear resistance (even though 440A is only HRC 53 and 420HC is HRC 55 WOW) this is because of the higher carbon and chromium content in the 440A and even more (carbon that is) in 440C! However, 420 HC is tougher, in that it is less brittle! This should be NO surprise considering the alloying elements!

There is absolutely nothing that I saw in the Timken literature that disputes anything that has already been said i.e. D2 is better than 440C, and 440C is better than 440A, and 440A is better than 420 HC, with regard to edge retention. However, M2 will beat any of those steels, and it oughta since it is higher in vanadium (strong carbide former) and tungsten (damned good carbide former and hard carbide to boot).

By the way, I'd bet you that if we took (4) Rockwell "C" scale testers and tested the same knife (lets say it had a TRUE Rockwell "C" hardness of 55) on all (4) testers, 5 times each (20 measurements) that we could easily get a range of readings for the exact same knife blade that ran from HRC53 to HRC 57 when measured as closely as possible in the same place. Newsflash, ROCKWELL TESTERS AREN'T THAT ACCURATE!

Perhaps you simply misunderstood the information in the link, since it is afterall in english which isn't your native language.

Have a great weekend.

ASS_CLOWN

ASS_CLOWN: That is one of the best lie about steels I ever seen. Or it could not be a lie, but they are comparing potatoes with apples. For example comparing with 440A hardened to 53HRC, it could be pretty shit knife, standard hardening to 440A is at least 55, or 57 more common. All steel are mentioned under or over hardened, so their properties look much worse then they are . . .And there are no numbers, no concrete numbers of toughness, wear resistance, ultimate bending strength etc. It looks like very big gimmick . . .

Try to look at the tables of reputable steel producers, like Bohler or Crucible . . .


And what to say, 420HC is one of the most shit steels on market, its only advantage is low price and big advertising

Jiri

And about D2 A2 etc., this steels are far better than that 420HC, except corrosion resistance, but with proper care or blade finish it doesn't matter. But this steel are a little bit out of date now, today powder steels have much better properties. For example, standard Chris Reeve is from A2, but limited series are from CPM-3V, CPM-3V is about two times more tough and also much better edge keeper . . .

What to say, it is like comparing .450 black powder express with .450 nitro express . . .