Stable edge steels (NOT TOUGHNESS)

[Drebs]

Which steels have the most stable edges? people always say that it’s the toughest steels, but that’s not always true. Tough steals or shock resistant steels resistant to the point of not breaking weather dropped or through lateral force that doesn’t always correlate to edge stability. Eg spring steel 1080, 1085, 1090 etc will take abuse and you can’t break it but the edge will roll.

I would rather get micro chips when I have the use the knife and sharpen in our later than god a roll if I screw up .

It seems to me the top are rex 45, 4v and m4 for pure edge stability ( lack of rolling and chipping ) we’ve all seen big brown bear (deadbox hero) comparing m4 to rex 45 edge stability I wonder if you did that test to maxamet if it would hold up for chip out due to brittleness .: maybe I’m missing k390? Maybe will say cruwear, yes it’s tough but seems to not be the league of rex 45 in EDGE STABILITY. Anyone have any input haven’t found a thread on it only picking up what I can from here at there.

[sal]

Hi Drebs,

Welcome to our forum.

sal

[JD Spydo]

This may not qualify for what you're looking for. But I will say that my M390 Military model has endured a lot of hard use and I don't sharpen it very often. I've used many of Spyderco's great blade steels over the years and for hard use and over EDC uses I really like M390.

Not at all saying it's the best>> but it has served me very well in the past 3 to 4 years. I would not hesitate buying another M390 folder or fixed blade.

[TkoK83Spy]

I like stability as well. For me, it's been Rex45 and 4V. 1a and 1b in my book. Less need to sharpen the better, though touch ups are also very quick on both.

[Karl_H]

“Edge stability” is a function of edge geometry, strength, and toughness. As far as I am aware, there are no well controlled edge stability tests for Spyderco knives.

Larrin’s graphs that plot toughness vs. hardness (on knife steel nerds) are probably the best available resource for comparing different steels.

[DukeNiemand]

I'm sure BBB will be along soon to comment with more info, but based on a lot of the tests I've seen, and my own experiences, Rex 45, K390, and 10V should definitely be among the front runners.

[SG89]

I like stability as well. For me, it's been Rex45 and 4V. 1a and 1b in my book. Less need to sharpen the better, though touch ups are also very quick on both.

Do you have any 3V, Rick? My bark river is 3V and I've been wondering if I should try a 4V spydie unless you think it's too similar to Rex45? (edge holding and sharpening-wise)

[Drebs]

Yes geometry plays a factor but things being equal Rex 45 blows s30v, m390 etc out of the water. Just watch big brown beats video comparing identical geometry m4 vs rex 45. So geometry is an important factor but certainly not the answer. Also it was a lateral strength test.

I’ve read Larrin say the tighter the microstructure of the steel the better the edge stability, however he also says the tighter the grain microstructure the stronger.. seems tight micro structures ran at high hrc equates to edge stability. So then aeb-l must be up there.

[Cambertree]

In my usage, AEB-L and 52100 are probably the most stable in thinly reground edges, resisting both chipping and rolling extremely well.

HAP40 also deserves a mention.

All steels will yield at some point.

[elena86]

AEB-L, K390, 52100

[dj moonbat]

Probably something like 1095 or 52100, where there’s enough carbon to make it hard but little other carbide-forming material to disrupt the microstructure. I don’t think there’s that sharp a distinction between tough steels and edge-stable steels; the same carbide pockets that contribute to failure tend to contribute to fracture.

[TkoK83Spy]

I like stability as well. For me, it's been Rex45 and 4V. 1a and 1b in my book. Less need to sharpen the better, though touch ups are also very quick on both.

Do you have any 3V, Rick? My bark river is 3V and I've been wondering if I should try a 4V spydie unless you think it's too similar to Rex45? (edge holding and sharpening-wise)

I have not tried any 3V, but between Rex45 and 4V for my uses they are 1a and 1b for me. I've got both, in both the Shaman and Manix and they are very similar... similarly awesome! Their so great that I haven't even had to sharpen either steel yet across those 4 knives. Just touchups, which were a breeze. So yes, to me they are quite similar.

If you're thinking of a St Nick's exclusive... there's nothing wrong with having your Rex45 satin blade, and a 4V dlc coated blade. Similar yet so different :)

[JD Spydo]

In my usage, AEB-L and 52100 are probably the most stable in thinly reground edges, resisting both chipping and rolling extremely well.

HAP40 also deserves a mention.

All steels will yield at some point.

That's an excellent point you make "Cambertree" . When I visited with a few of the staff members of Crucible at one of the BLADE Shows one of their guys told me that "ALL BLADE STEELS" have their "strengths & weaknesses". I believe that too.

OH sure at some point in the future ( and maybe the near future) we will see what can truly be defined as a "SuperSteel". That will be head and shoulders above what we call supersteels now. Just look at the awesome progress they have made in the field of ceramics. I do believe we'll see steel make progress as well.

[Larrin]

Resistance to deformation is measured by hardness (not controlled by steel but by heat treatment). Resistance to chipping is measured by toughness. So asking which is the most stable but without toughness doesn't make any sense. An edge which loses cutting ability to either chipping or rolling is still not cutting as well. The edge has to have a more obtuse angle to make up for lower hardness and/or toughness.

[steelcity16]

In my usage, AEB-L and 52100 are probably the most stable in thinly reground edges, resisting both chipping and rolling extremely well.

HAP40 also deserves a mention.

All steels will yield at some point.

AEB-L, K390, 52100

AEB-L and 52100 are two steels I would like to see more of. It's too bad that DLC 52100 Manix wasn't as popular as it should have been. If that one had never been done and DLT or BHQ did the exact same Manix and hyped it up and did a drop it would have sold out in minutes.

I'd like to see these steels in some new Military models and in Enduras and Police LWs. DLC on 52100 makes sense though because it is the most corrosion prone of any steel I have used.

[JuPaul]

In my usage, AEB-L and 52100 are probably the most stable in thinly reground edges, resisting both chipping and rolling extremely well.

HAP40 also deserves a mention.

All steels will yield at some point.

AEB-L, K390, 52100

AEB-L and 52100 are two steels I would like to see more of. It's too bad that DLC 52100 Manix wasn't as popular as it should have been. If that one had never been done and DLT or BHQ did the exact same Manix and hyped it up and did a drop it would have sold out in minutes.

I'd like to see these steels in some new Military models and in Enduras and Police LWs. DLC on 52100 makes sense though becauseit is the most corrosion prone of any steel I have used.

Same in my experience, with far more issues on my satin 52100 pm2 than on my dlc manix. Dlc does seem to help. Even though some argue it doesn't prevent corrosion, it definitely "absorbs" oil, which certainly does prevent corrosion.

[Drebs]

Resistance to deformation is measured by hardness (not controlled by steel but by heat treatment). Resistance to chipping is measured by toughness. So asking which is the most stable but without toughness doesn't make any sense. An edge which loses cutting ability to either chipping or rolling is still not cutting as well. The edge has to have a more obtuse angle to make up for lower hardness and/or toughness.

So I know your not one to tip your hat but what common steels are at the greatest intersection of these two roads in common use? I quite interested in 4v vs rex 45 vs cruwear vs 52100 vs k390vs m4. In terms of edge stability, meaning on my m390 I don’t know what in the world I do I understand what a knife is and what I tool is and how to “use” a knife properly but my edge would say otherwise.

So in shawns Rex 45 vs m4 video trying to chip the edge on brass. We know the Rex 45 is harder but the m4 might be tougher ( maybe I’m wrong but I thought toughness was resistance to shattering shear lateral force before breaking) because it’s not a brittle. However Rex 45 beats the m4 in edge stability in that video does that mean it’s both harder and tougher ?

[Cambertree]

All steels will yield at some point.

That's an excellent point you make "Cambertree" . When I visited with a few of the staff members of Crucible at one of the BLADE Shows one of their guys told me that "ALL BLADE STEELS" have their "strengths & weaknesses". I believe that too.

OH sure at some point in the future ( and maybe the near future) we will see what can truly be defined as a "SuperSteel". That will be head and shoulders above what we call supersteels now. Just look at the awesome progress they have made in the field of ceramics. I do believe we'll see steel make progress as well.

Thanks JD. :)

Yes, I sometimes think there’s an inordinate focus on wear resistance in the modern market, because it’s an easy thing for backyard Youtube reviewers to test.

When people ask for steels to be run harder and harder, they often don’t take into account that for a minor hardness increase, there may be large reductions in toughness, edge stability and corrosion resistance.

I think Spyderco’s heat treatments are usually optimised to hit a sweet spot where all those factors are taken into account.

Who among us uses knives until they are completely dull, anyway?

Steelcity16 and Julia: I agree, I’d like to see more DLC coated 52100 blades.

That format would be great for fixed blades as well.

Like a Waterway sprint maybe?

A while ago, a forum member wrote some great posts explaining the structure of DLC coating, and how it has kind of ‘micro fissures’ running through it. So it really does work well for retaining a protective oil coat.

Sorry, I don’t recall who it was, though.

[Ankerson]

Resistance to deformation is measured by hardness (not controlled by steel but by heat treatment). Resistance to chipping is measured by toughness. So asking which is the most stable but without toughness doesn't make any sense. An edge which loses cutting ability to either chipping or rolling is still not cutting as well. The edge has to have a more obtuse angle to make up for lower hardness and/or toughness.

Kinda hard to cut anything with a blade that the apex is folded over or compressed.. LOL :D

It's all the balance really, the designers have to balance the performance using all of the factors combined if they want a high performance blade.

EVERYTHING matters, HT, Geometry, blade design, steel choice and the end use of the design.

It all has to balance out and compromises have to be made.

[bdblue]

Apparently when you push on the edge and stress the steel it is going to fail. If it is a brittle steel it will chip, if it is a tough steel then it will roll. But either way you exceed the steel's limit and it fails. If you want a more stable edge then you need a stronger steel, raise that limit. A stronger steel is a steel with higher hardness. So the most stable edge will probably be the steel that you can harden the most.