Favorite steel!

[AlexRus]

CPM S125V,
CPM S110V,
M390/CTS-204P/CPM-20CV,
CPM S90V

[Hopweaver]

S90V checks all the boxes for me.

[JonLeBlanc]

52100 for sure

[Wartstein]

HAP 40, probably

[Sumdumguy]

Favorites:

1. LC200N. I love this steel, period.

2. M4. Tough as nails tool steel with decent corrosion resistance(stay tuned).

3. VG-10. This was my favorite all around steels, but I would swap it across the board for LC200N. However, with the sheer amount of Spydercos that use in this steel it easily makes the top 3.

Honorable Mention:

4. Superblue. I love the performance this steel offers, but it just can't quite match M4.

5. S90V. Great all around stainless, but all the knives I like in S90V come in LC200N...

[Baron Mind]

s90v and Cru-wear. The rest are pretty great too, honestly.

[cycleguy]

VG-10, not overly hardened.

CG

[gigem95]

If I had to pick one, M390 would probably be it because it's the most well rounded steel that I have used. With that said, I do have a lot of love for Maxamet, Cru-wear, and S110V, and each has it's own purpose and application.

[Mako109]

- M390/CTS-204P/CPM-20CV
- CPM-M4
- CPM S35VN

[murphjd25]

M4, M390, S35VN, PSF27.

[Supacede]

VG-10. I'm an easy date.

[Zenith]

Nitrobe-77

[RazorSharp86]

Superblue, LC200N and Maxamet really impressed me in the last year or so.
I’m a hardcore fan of ZDP-189 as well as K390, as well.

[ThomS]

My favorite steel is the one on my next knife. :-)

[youmakemehole]

1. High performing stainless: a few months ago I might've put M390 as the winner of this category, but LC200N has been probably dethroned the king as of late.

2. High carbide tool steel: Spyderco's REX 45 takes this spot, their M4 is awesome for something a little toothier and HAP40 not too far behind REX 45 as well, but I think the REX45 is ht'd a lot better than what Hitachi does with the HAP40 though.

3. Fine grained carbon steel: 52100 is a beautiful steel especially in a PM2 or PM3, these types of steels are great if you enjoy sharpening and maintaining your blades as a hobby. Idk why Spyderco does not try to have a go at pushing out some folders made in Sandvik steels, I think given their expertise they could make something just as amazing if not better than their 52100 with Sandvik's 14c28n or 12c27.

[Holland]

M4 was my favourite for years, but I think Hap40 may have taken over the number1 spot for me

[missouried]

CPM-s110v
CPM-s90v
S35VN
ZDP-189
M4
Maxamet

I can be pretty happy with any one of them, but S35VN is my favorite.

[JD Spydo]

VG-10. I'm an easy date.

Yeah me too !!!! I still use my older VG-10 Spyderco models quite a bit and I find it to be a great all purpose blade steel that's relatively easy to maintain and sharpen.

Now in the Supersteel category I still like M390 the best for several reasons. My main EDC is M390.

Now for the Golden Oldies department I still like a couple of my older ATS-55 Spyderco models.

[RippyD]

M4, M390, S35VN, PSF27.

I just started using a PSF27 Mule. This is awesome steel. For me it's very similar to K390 in terms of edge holding. Possibly better?

K390 if I had to pick one. Or maybe M4? I really don't have issues with any of the steels Spyderco uses. I didn't get an Rex 45 so can't compare.

[Cambertree]

All things considered, K390 for me. I've had the Edgematters Pingo, the Urban and the Police 4.
Once the blades have been thinned out behind the edge, I love the crisp bite of this steel in both coarse and finely finished edges. It seems relatively tough considering the high carbide volume. IIRC, Sal mentioned the Poilce 4s are in the range of HRc 64/65 and an Urban he tested came in at 62.5. It seems to keep that high level, super fine edge a bit longer than many other knife steels, too.

At this point I'd probably get anything that came out in K390, but the Seki series in that steel would be fantastic - especially the Stretch and Dragonfly.

HAP40 is on most of my main everyday working knives (Dragonfly, Stretch, Endura, Manbug).

ZDP189, Cruwear and CPM M4 are also close contenders.