Opinions of super blue blade steel please

[Cliff Stamp]

...I'd think a toothy edge would have less edge retention because I'd think the very tiny teeth might snap off

It depends on what you are cutting and how. If you are :

-push cutting
-cutting hard materials

then a higher polish will provide higher edge retention, however if you are :

-slicing
-cutting soft materials

then both initial cutting performance and edge retention can be increased with a coarse finish.

If you want to see this on a macroscopic scale then take two saws :

-one with a very coarse TPI
-one with a very fine TPI

and try cutting some very soft and very hard wood.

In this case besides corrosion resistance and purchase price would vg10 have any advantage?

I would not think so.

From your answer, it sounds like you don't gain much from Superblue, unless you want to cut fish for sushi and you do this for hous on end.

If that is what you take from what I wrote then I don't know what to say aside from the fact that nothing I wrote implies that.

I can't give you the answer you want. There are lots of people who will readily give you very simple and very exact answers to your question. Now they will be wrong, but they won't be complicated.

The reality is that the answer to your question isn't so trivial that you can just pick a number, if it was I would have just given it. Anyone who gives you such a simple answer either :

a) doesn't know what they are talking about

b) is trying to sell you something

Here is a question :


What has better edge retention 1075 at 52/53 HRC or VG-10 from Spyderco at 59/60 HRC?

Does it change if I add more detail :


What has better edge retention slicing cardboard with a 600 DMT finish - 1075 at 52/53 HRC or VG-10 from Spyderco at 59/60 HRC.

How about even more detail :

What has better edge retention slicing cardboard with a 600 DMT finish - 1075 at 52/53 HRC or VG-10 from Spyderco at 59/60 HRC with a 14-16 dps micro-bevel and a 7-9 dps primary bevel.

Most people will immediately jump to VG-10 to all questions, if you are aware of edge stability then you should hesitate when they see 7-9 dps behind the micro-bevel.

Before you reach your final conclusion :



This is a 50X magnification shot of a Lum, the damage is too extensive to get in the FoV at 50X magnification as it is visible by eye.

The answer to the above is in this case it was the 1075 blade at 52/53 HRC because the VG-10 blade was fracturing and losing large pieces out of the edge and the 1075 was just taking slow wear.

However when the VG-10 doesn't fracture then it has a about a 50% improvement in edge retention, but if the cardboard is hard and stiff enough that it causes the force to rise above a critical level then the VG-10 starts fracturing.

This kind of extreme fracturing can't happen with 1075 at 52/53 HRC (and much higher) because it is much more stable at thin cross sections than VG-10. But again :

-if you are cutting soft materials
-you are cutting slow
-not exerting much force

then you won't fracture VG-10 and thus it will pull ahead as it reduces to wear resistance mainly.

The answer to the question is :

-if the cardboard is hard/stiff enough to cause fracture, then 1075, otherwise VG-10

Now at some point if you keep increasing the primary bevel angle the VG-10 will stop fracturing - however the angle that is necessary to stabilize it will depend on :

-the stiffness of the cardboard
-the thickness
-the speed of the cut
-control/efficiency in the cut

and so again you can't simply say VG-10 will stabilize at 15 dps (or whatever) anyone who says that is just making things up. The question is then do you want an answer which is simple (and wrong) or do you want the truth?

[GoodEyeSniper]

in other words, the answer to the question is 42.

[Blerv]

Thanks for the write-up Cliff. :)

[xceptnl]

Thanks for the write-up Cliff. :)

Agreed, this is one of the most cut to the bone posts we have seen from you in a while Cliff.

[WorkingEdge]

Cliff - in regards to push cutting versus slice cuts, in a push cut, the blade only moves in one axis but in a slice cut, the blade moves in two axis. There is some pressure against the medium being cut as the blade is moved in a slicing motion. Doesn't that pressure against the medium cause some push cutting to occur as well during a slicing cut? If that is the case, then if I sliced with more pressure against the medium, would at some point as pressure increases, attributes of the edge that favors push cutting become more advantageous and vice versa?

Sorry if this is a confusing post. I find myself having a hard time trying to describe this.

[Cliff Stamp]

If that is the case, then if I sliced with more pressure against the medium, would at some point as pressure increases, attributes of the edge that favors push cutting become more advantageous and vice versa?

Yes, you are exactly right in the description and conclusion. Essentially :

-a pure slice has an infinite horizontal/vertical travel ratio (the draw is much longer than depth of cut)
-a pure push has an infinite vertical/horizontal travel ratio (the depth of cut is much longer than the draw)

It is fairly easy to do an almost perfect pure push cut, but not so for a slice as you have to travel into the material to actually cut it.

You need to then find the balance of edge finish which has :

-enough slicing aggression (sawing) to maximize the draw
-not so much tooth that it requires too much force to push the blade into the material

In general the Spyderco medium is a nice finish for a lot of work, as it isn't so rough that it is poor even in kitchen chopping / dicing and still handles ropes and cardboard well. It is one of those finishes that if I didn't know what I had to do would be a good choice. I often leave blades with that finish for people who ask me to sharpen knives and I don't know much about what they do with them.

[WorkingEdge]

Thx, Cliff.

I now have two super blue blades (endura and delica) and will play with angles a little bit. Figure I'll go thinner edge with the shorter blade.