edge retention of serrations in really abusive cutting

C

Cliff Stamp

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I needed some rubber for firestarters / signals and so :

http://i7.photobucket.com/albums/y269/CliffStamp/Spyderco/Salt/tire_flat.jpg

was utilized. I had a bunch of knives and this was quickly discovered :

1) The UK Pen cut well, but putting the point through the material as well as cutting could cause the blade to fold if you were in a hurry or didn't use a lot of care. I removed a strip without problems, but based on working with it and making it fold intentionally to see how difficult it would be, I would want a locking folder.

2) Sharpness made more of a difference than profile. Once the initial cut is made it isn't difficult to get the rubber to seperate and thus a Delica cut just as well as the Pen or Poliwog, and I had reprofiled the Pen to a 10 degree edge bevel.

3) You want a sharp point to start the cuts, the Dodo went in easily and it was the only knife that didn't even need a slice. Just press and pull and the side of the tire was gone. The Alantic Salt aggressively cut through the side, but starting a cut took some time.

4) You can actually cut it with a fine saw, assuming you can open a hole anyway, it is was less effective than a knife, it chews it up more than cuts it, basically the entire length of the saw blade would cut as much as the Delica with one slice each and it took a lot more force with the saw.

http://i7.photobucket.com/albums/y269/CliffStamp/Spyderco/Salt/tire_sliced.jpg


Cutting the tire into pieces was much harder, they are reinforced with steel wires and the plain edges blades could make no headway, just a few slices, and the edges were all reflecting light, VG-10 or S30V made no difference. However the Alantic Salt chewed through it :

http://i7.photobucket.com/albums/y269/CliffStamp/Spyderco/Salt/tire_sectioned.jpg

This took about five minutes and I had to stop three times, it needed a fair amount of force to cut through all the metal, the rubber in contrast was really easy.

At the low right of the picture you see a piece of wood which is pointed ,that was done with the Salt after the tire cut, the knife could still readily cut woods, in fact did so better than the plain edged knives and yes :

http://i7.photobucket.com/albums/y269/CliffStamp/Spyderco/Salt/alantic_salt_tomato.jpg

This steel cutting however did put a fair amount of wear on the Salt, mainly it rounded the points, however there was still a lot of cutting left in the knife.

-Cliff
 
Wow, what a great review! It warms my heart to hear the Dodo performed so well, hawkbills definitely have their advantages;). The wire cutting is also a great testiment to the eating power of SE, I would't want to put my PE through that.
 
This just proves what I've been saying all along. Using a fine premium grade of steel like S30V or VG10 for a serrated blade is a waste of good steel. Any serrated blade cuts well in a situation like this test. I jokingly said the other day that Spyderco could just make H1 the default steel whenever they did serrations because I venture to say that even a bottom of the barrel 400 series steel would cut well in a test like this so long as the blade is serrated. I wasn't serious but this test proves just how good a blade can perform with the right serration pattern; even in a hard to cut medium like a thick tire.

What seems to be more important is the type of serrations on the blade and not the steel so much. I think that is why those Cold Steel little Ready Edge and Para Edge knives are so popular with some of the hunters I know that use them as small capers for detail work. They are scalpel sharp our of the box and the serrations make them keep going and going and going like the engergizer bunny even though they are just a cheap 400 series steel or AUS6A depending on which you buy.

Great test Cliff. I have that Atlantic and reprofiled the tip to a better point after I Waved the blade. It does cut up a storm and has fast earned a place in my pocket. I had it on me all day today while cutting fire wood. I love using it in the kitchen too. Its a great food prep knife for sure.

STR
 
STR said:
This just proves what I've been saying all along. Using a fine premium grade of steel like S30V or VG10 for a serrated blade is a waste of good steel. Any serrated blade cuts well in a situation like this test. I jokingly said the other day that Spyderco could just make H1 the default steel whenever they did serrations because I venture to say that even a bottom of the barrel 400 series steel would cut well in a test like this so long as the blade is serrated. I wasn't serious but this test proves just how good a blade can perform with the right serration pattern; even in a hard to cut medium like a thick tire.

What seems to be more important is the type of serrations on the blade and not the steel so much. I think that is why those Cold Steel little Ready Edge and Para Edge knives are so popular with some of the hunters I know that use them as small capers for detail work. They are scalpel sharp our of the box and the serrations make them keep going and going and going like the engergizer bunny even though they are just a cheap 400 series steel or AUS6A depending on which you buy.

Great test Cliff. I have that Atlantic and reprofiled the tip to a better point after I Waved the blade. It does cut up a storm and has fast earned a place in my pocket. I had it on me all day today while cutting fire wood. I love using it in the kitchen too. Its a great food prep knife for sure.

STR
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STR you say that like H1 isn't a premium steel in SE. Considering the 68 Rc hardness rating in SE, H1 better kick butt in this tire test.:eek:
 
STR said:
This just proves what I've been saying all along. Using a fine premium grade of steel like S30V or VG10 for a serrated blade is a waste of good steel.
Click to expand...

I don't know if I would go that far, different steels can allow different geometries, and would have a much slower rate of wear.

What seems to be more important is the type of serrations on the blade and not the steel so much.
Click to expand...

That is an extension of what Mike showed on rec.knives when he reprofiled knives and adjusted the finish and found that you could really get better cutting and edge retention based on geometry over steel. Joe showed this with a bunch of high end knives showing rope cutting improvment of hundreds of percent. Of course take the same geometry and now refine it with better steels and you push it even further. Who would not like to see a M2 serrated blade for example, or S90V for stainless.

zenheretic said:
Johny Mullet is gonna be real pissed when finds out his best tire has been vandalized
Click to expand...

You must not have much experience with mullets, dude, they are "speed holes".

-Cliff
 
No worries, I was planning two pieces of work with two serrated spydercos, one was fairly normal, I was going to run it over a really wide range of materials compared to two plain edges on the medium/fine finishes and then I was going to do another fairly silly one where I redid the ginsu commercial by "borrowing" my brothers video camera. He returned it however as the memory card didn't work. I may still do it if if gets a new one.

The plain/spyderedge comparison is underway now, papers, cardboard, plastics, fabrics, foods and woods are about half done, most of the results are not surprising, some are really interesting like take a thick piece of rubber and cut it with the edges and see what happens, the serrated blade cuts *many* times to one better, the Dodo does really well though as the point is similar to a serration peak.

The Dodo in effect has a lot of the benefits of a serration pattern, you can even thick of it as just one big serration scallop. It is a lot more utilitarian than most people probably think.

-Cliff
 
No, I consider H1 to be a premium steel all the way. I've said that before in my posts.

STR
 
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