[HN Gopher] CPM MagnaCut - The Next Breakthrough in Knife Steel
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CPM MagnaCut - The Next Breakthrough in Knife Steel
Author : topsycatt
Score : 96 points
Date : 2021-12-26 20:42 UTC (2 hours ago)
(HTM) web link (knifesteelnerds.com)
(TXT) w3m dump (knifesteelnerds.com)
| gxt wrote:
| Since I presume steel is a more or less uniform substance
| compared to biological processes, why is metallurgical research
| still more or less experiment first?
|
| Shouldn't it possible nowadays to bruteforce a search for an
| alloy of any given properties using computer simulations of the
| atomic or molecular structures?
| bob_loblaw wrote:
| Very cool to see this pop up on Hacker News. I'm into pocket
| knives, and Larrin's new steel is generating a lot of hype among
| knife users and makers.
| MrMember wrote:
| Really interesting read. It's cool that a company like Crucible
| was willing to consider a proposal for something as expensive,
| time consuming, and potentially fruitless as a new steel from
| essentially someone off the street.
| bob_loblaw wrote:
| Larrin's father is a famous custom knife maker who worked with
| making his own Damascus-style steel. Larrin, though his father,
| is well-known among the knife community.
| Straw wrote:
| How does this compare to Japanese steels such as HAP40 and Aogami
| White/Blue/Super?
| bob_loblaw wrote:
| If you look at White/Blue/Super funny they will rust. HAP40 is
| a high-speed tool steel. CPM M4 is a good comparison to it.
| MagnaCut will offer corrosion resistance that you don't tend to
| see in Japanese steels. MagnaCut will have better edge
| retention than White/Blue/Super. Those steels are low-alloy and
| rely on high hardness for wear resistance. MagnaCut has
| vanadium and niobium plus it can get pretty hard as well.
| MagnaCut is so far ahead of White/Blue/Super in this regard.
| Japanese steels are known for being great to sharpen (even
| HAP40). From what I have read, MagnaCut sharpens well.
|
| If we say that MagnaCut = stainless 4V and HAP40 = CPM M4, then
| HAP40 should have some more edge retention but less toughness
| when compared to MagnaCut. The differences aren't all that
| great. Corrosion resistance is the real difference maker.
| nimbius wrote:
| I'm sure this will get down voted as its a Luddites call to arms,
| but all my cutlery is simple high carbon steel.
|
| Its cheap, holds an excellent edge, and in the kitchen it
| develops a wonderful rustic patina. For a pocket knife, a few
| drops of oil once or twice a year will keep it in good order, or
| you can chemically blue it if that suits your style as well.
| rkagerer wrote:
| This is a huge article. Can anyone give a 1-paragraph synopsis of
| its main thrust?
| TaylorAlexander wrote:
| new steel good
| bob_loblaw wrote:
| MagnaCut is the first knife steel that does the best job of
| balancing edge retention, toughness, and corrosion resistance.
| It is basically a stainless 4V (if that means anything to you).
| Larrin focused on reducing the amount or chromium needed. Lots
| of steels will dump chromium into the steel to help corrosion
| resistance. This only helps if chromium remains in solution and
| not forming carbides with the iron. Chromium carbides don't
| offer much in the way of wear resistance (unless you have a ton
| of them like in ZDP-189) and they are large carbides
| (relatively speaking) even after the particle metallurgy
| process. Basically, you give up toughness when helping
| corrosion resistance (ignoring steels with nitrogen). Larrin
| uses a lower amount of chromium than you would expect, but it
| remains in solution. So you get the stain resistance you want
| without the chromium carbides.
|
| Other benefits of the steel include grindability, which means
| makers can spend less time and abrasives on shaping the knife.
| You can obtain higher hardness than a standard stainless steel,
| which helps with forming an apex and removing the burr
| (sharpness for lack of a better word).
|
| Spyderco, a major player in the knife world, has a line of
| knives called their Salt series. These knives are supposed to
| be as rust-free as one can make. MagnaCut will first enter
| their catalog as a Salt knife. This was a big shock given how
| well LC200N (nitrogen-based steel used by NASA for ball
| bearings) can resist rust and remain tough (wear resistance
| isn't anything special though).
|
| Bottom line, Larrin built a well-balanced steel exclusively for
| knives. Many steels are adopted from other industries or were
| "knife-specific" but based on something like 440C, which was
| never intended for cutlery. So MagnaCut is upending the knife
| steel market by offering something you can't get elsewhere.
| notacoward wrote:
| Knife nerd comes up with an idea for how to make a steel with a
| novel combination of hardness / toughness, edge retention, and
| corrosion resistance. Persuades a real steel company to make a
| batch, which is tested eighteen ways from Friday by him, the
| company, and a bunch of knifemakers. Result turns out to be as
| good as predicted, maybe even a bit better.
|
| Bonus making it even more relevant to HN: most of the
| "discovery" was done via software, before any physical
| experiments (which are hard and expensive in this case). The
| fact that this new approach yielded good results is promising
| wrt developing steels with different properties.
| BatFastard wrote:
| Great looking knife, but 10 minutes of looking doesn't reveal
| where to buy one!
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