Matus wrote: ↑Fri Apr 23, 2021 9:15 am
Wartstein wrote: ↑Fri Apr 23, 2021 4:52 am
BD1N is great and for me sharpens to a very keen edge even easier than VG10.
In my use it seems to be not to bad in edge retention too.
But in Larrins about 10000 times more
objective testing BD1N has less edge retention than even VG10 and so certainly below Spy27 (though of course edge retention is just one of many parameters concerning performance).
You make a very good point. I am certainly not ignoring Larrin's results. The relevant difference that one should not forget that Larrin tests steels with a certain HT, while most other testers test knives (with a certain HT). In theory, the Catra test should gave us some roughly (and in a relative way) comparable results to say 'feet of cardboard' real life tests, but the differences due to different HT will remain, since per se Spyderco will have different details of the HT (for the better or worse) than Larrin.
One can see this for example in how S30V performs - in Larrin's tests it is on par or better than Cruwear, M4, 4V, etc. while in the cutting tests with (mostly Spyderco knvies) S30V never manages to perform past these steels. So there are some systematic differences which I can only imagine are related to the fact that these two tests are simply different and also because the heat treatments of the testing subjects most likely differ.
Since I am interested in a certain knife (here Para 3 LW) and see it perform very close in BD1N and Spy27, I am inclined to keep the BD1N and save some cash.
You are right of course that the heat treat can make a significant difference, and indeed the BD1N Larrin tested is in the 60ies, the VG10 in the 61es, but S30 V is tested in the 59es, 61es and 64es, and even in the 59 hardness range it has significantly better edge retention than BD1 N in the 60 range (see Larrins chart in my post above) - also there you can see the increases in edge retention for several steels when hardness increases - if this is just roughly the same with BD1N, it would still at the very best reach VG10 edge retention if it were in the 61 hardness range like VG10 in the test (and not "just" in the 60 range).
And: There is a direct quote from Larrin from this post (
viewtopic.php?t=86503#p1416623):
"... BD1N only has ~0.90% carbon plus a little nitrogen, and doesn't have any vanadium. I don't know how it would be testing much above VG10 at equivalent hardness and edge geometry"
So if Spy27 is close to S30V, it should beat BD1N easily in edge retention.
Actually I trust Larrins test more than other "edge retention tester" on youtube - and so i believe that S30 V has better edge retention than Cruwear, M4, 4V, even if different hardnesses are calculated - this is exactly what the chart shows!
Anyway: I have to admit that I was totally surprised how long my BD1N Manix LW DID actually hold an edge! I even started a thread on this cause I could hardly believe it. Subjectively clearly better than VG10...
So I think that to a more or less degree with the youtube testers factors like different grinds angles, how coarse or fine an edge is, different levels of sharpness come into play.