Ok I gotcha now and I agree. An awesome HT is more important in the making of a good blade then the actual steel itself. You can have a blade made of S35VN with a crappy HT and a blade made of 440A with a outstanding HT and the blade made of 440A would be the better blade even if it's the more inferior steel of the two.
It's funny and ironic you used 440a as this example.
I've grown to view CTS-BDZ-1 as a modern day, more refined version of 440a...
(Not to be confused with cts-BD1 or cts-BD1N, both completely different animals).
The only real difference between the 2 is much less chromium in BDZ-1, but........
440a has a long history of being used in stainless razor blades, and not only budget blades, but even custom blades (mostly of yesteryear, but regardless)... With a good reputable foundry, hitting all their marks, and a solid heat treat, 440a even today still makes a decent enough, highly rust resistant and tough stainless blade... is it a "super steel", absolutely not, but when well made it is a decent knife none-the-less...
(The main problem in today's market isn't the nomenclature itself in-as-much as it is the less then reputable manufacturing practices of many "budget friendly" 440a makers in the shadow of the modern ever evolving steel market of the new millenium)
In comes Carpenter (CarTech), and CTS-BDZ-1...
Sure there is much less Chromium then what's in traditional 440a, but CarTech is not your traditional run-of-the-muck steel foundry making every day run-of-the-muck traditional billet steel either. Just as seeing "CPM" in front of a steel name makes peoples ears and ....... perk up, "CTS" is no slouch in the steel industry, and is widely considered one of the industry leaders, especially here in the U.S.
State of the art vacuum processes, titanium alloys, NASA contracts, industry wages WELL north of average, (not to mention their buyout of another long time local competitor, Latrobe Specialty Steels, a little while back), Carpenter is certainly no slouch to the steel business, and their "CTS" branded steels are specific to "consistant fine edge holding" steels for knives and tools, and CTS-BDZ1 was specifically geared towards razor blades...
I mean, sure, they cut the amount of chromium down a bit from your classic billet 440a, that everyone from here to pakistan can make nowadays, but, they also have a state of the art facility doing state of the art metal stuff, with a world class reputation on the line, and even a "simple stainless" like cts-bdz1 (440a minus some chromium), is held to a much higher degree of tolerances and processes then your average typical "investment casting" and/or billet foundry would hold 440a to...
So that said, if you can guarantee a much more uniform melting matrix and distribution of elements, via a much better and more controlled process, then truth is you don't need as much Chromium in the matrix to still get an equally stainless result, because of even distribution vs. total carbon content, AND the resulting less overall and more evenly distributed chromium results in less (stray) carbides, which also allows for better edge stability in very fine edges, (like razor blades), while still retaining a very uniform stainless properties, AND overall better toughness, which is exactly what the steel was initially designed to be used for....
In a nutshell and long story short, 440a made a pretty decent stainless razor blade steel (thin edges) for quite some time, and it even made a pretty decent knife, especially years ago.
Years of technological advances over the years however, and Carpenter being among the industry leaders, (like Crucible(cpm), Voestelpine(bohler-uddehelm), Sandvik-Coromant, Yasugi(hitachi)), none of which are making any claims as the largest "producers" of steel persay, as there are foundries/companies out there pumping out your basic steels by the metric ton on top of metric ton multiplied to multiple exponents and then some, but rather we're talking about some of the industry leaders regarding "innovation and advancement" of the metallurgical industry as a whole... new metals, new processes, new technologies, etc), Carpenter found a way to make your common 440a stainless razor blade steel from the 40's and 50's, much cleaner, more uniform, and consistent from batch to batch, and basically an all around better steel, without sacrificing a thing about the original....
So is it a "super-steel", lol, absolutely not!!!
but it is a very super and refined version of an original classic, (440a), that will make very suitable, very tough and stain resistant, very stable fine (even razor) edged cutting instrument, which should be consistant from batch to batch to batch, provided the process (final heat treat) is also consistant fron batch to batch to batch...
