M398 Steel Testing – Edge Retention, Toughness, and More

[Ramonade]

Seems that toughness aproximates the ones of S110V and Maxamet. Edge retention is interesting though !

When I see all these graphs (M398 article, Knife Steel Rated by a Metallurgist,...), Z-Max is the steel that really tickles my curiosity at the moment!

[Rymanz]

Sounds like it's around the ballpark of a high stain-resistant ZDP-189. I'm definitely keeping my eye out for this Mule!

[Razor G43]

I haven't really used a bad spyderco steel. I also have come to like easy sharpening steels. Getting old I guess. lol

[shunsui]

Interesting article. High carbides, stain resistant and high edge retention.
Low toughness, but It might be viable at something other than 62.8 Rc.
I think Spyderco runs S90V around 60 Rc.

If Sal's willing to buy the steel and play with it, I'm willing to buy a mule.

[Soanso McMasters]

New article summarizing a whole range of experiments I performed on the new Bohler M398 steel. I tested edge retention, toughness, corrosion resistance, heat treatment, and hardness. And I included some discussion on how it compares to other steels in its general category including S110V, S90V, S125V, S60V, and ZDP-189. https://knifesteelnerds.com/2020/10/26/ ... -and-more/

Interesting, thanks for the info! Have you ever rated K390 for toughness? I’ve yet to see it but I’m also a mouth-breathing idiot!

[Larrin]

If someone sends me some 1/8” K390 I can test its toughness.

[sal]

Hi larrin,

I'll see what we may have "laying around"? What size do you need?

sal

[Soanso McMasters]

If someone sends me some 1/8” K390 I can test its toughness.

If you take Sal up on his offer please let us know what you find out. I’ve been very curious about how K390 ranks among its peers.

[Larrin]

Hi larrin,

I'll see what we may have "laying around"? What size do you need?

sal

The individual charpy specimens are 2.5 x 10 x 55 mm and I usually test three of them. So a 3 x 40 x 55 mm piece would do it. 55 mm in the rolling direction. With a bigger piece I could do more hardness levels/heat treatments.

[Bemo]

Just gotta love this place!

[sal]

Hi Larrin,

Sorry, We have none in house.

sal

[yablanowitz]

You sent it all to Japan for Police Models, didn't you?

[TTFulltimer]

After weeks of trying I finally got two M398 Mules. One will go in my tackle box. Staying razor sharp is mandatory for cutting braided line. Slicing bait, cutting Fish Bites, cutting ropes of various sorts, mostly olefins in floating rope, and polyesters in paracord and non stretch ropes. Nylon in anchor lines, large diameters in super braid winch line. Salt water makes corrosion resistance a nice feature. It is all basically light use from an edge stability perspective.

The second will go to my son. He is my go to knife tester. If he does not break it, it most likely will not break. That one will get bolt on handles so if he does break it, the handles can go on another mule for testing. If he does not break it, I will put on some really nice wood handles.