Golden Colorado Heat Treat

Discuss Spyderco's products and history.
SubMicron
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Re: Golden Colorado Heat Treat

#21

Post by SubMicron »

curlyhairedboy wrote:
Sat May 16, 2020 6:42 pm
Re: chips VS rolls

An argument could be made from a durability perspective that deformation is preferable to crack formation and potential propagation.
Agreed. Above all, I'd rather have the required strength to resist deformation of any kind but beyond that I'd definitely prefer deformation to chipping specifically because of the possibility of crack propagation.

With how strong at the apex REX-45 is, and with S35VN's reputation for plastic deformation with compressive or impactful forces, I do suspect the OP's problem began during sharpening.
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sal
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Re: Golden Colorado Heat Treat

#22

Post by sal »

Hi SnackTime,

Sorry for your frustration. I guess you can always send it to us for a "Look-see".

sal
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Doc Dan
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Re: Golden Colorado Heat Treat

#23

Post by Doc Dan »

Albatross wrote:
Sat May 16, 2020 9:59 am
Might be worth checking for a wire edge. To me, it sounds like the apex possibly hasn't been fully cleaned up.
I was going to say this. You eat me to it. A wire edge not properly removed will cause this exact thing.
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AwayFromMySpydieHole
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Re: Golden Colorado Heat Treat

#24

Post by AwayFromMySpydieHole »

curlyhairedboy wrote:
Sat May 16, 2020 6:42 pm
Re: chips VS rolls

An argument could be made from a durability perspective that deformation is preferable to crack formation and potential propagation.
Sure, that argument could be made - but it would be slightly pedantic. We’re talking about small chips and small rolls, not huge cracks up the blade. A properly heat treated knife should resist cracking no matter what the failure point is at the apex.


You’d be surprised the abuse a very hard blade can take without cracking. Even heavily carbide laden steels. A small chip on the apex forming into a crack that splits the blade is probably so rare as to be statistically insignificant.


I’ve seen blades crack. Many of them. Never once have I seen a blade crack due to apex damage. Seen plenty of them crack from thumb studs being pressed in, or relief cuts being the start, or opening hole, etc. Never once a crack at the apex.

Take that for what it’s worth. I think you should worry more about a meteor falling on your head before a chip in your edge forming a large crack.
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Albatross
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Re: Golden Colorado Heat Treat

#25

Post by Albatross »

AwayFromMySpydieHole wrote:
Sun May 17, 2020 2:44 am
curlyhairedboy wrote:
Sat May 16, 2020 6:42 pm
Re: chips VS rolls

An argument could be made from a durability perspective that deformation is preferable to crack formation and potential propagation.
Sure, that argument could be made - but it would be slightly pedantic. We’re talking about small chips and small rolls, not huge cracks up the blade. A properly heat treated knife should resist cracking no matter what the failure point is at the apex.


You’d be surprised the abuse a very hard blade can take without cracking. Even heavily carbide laden steels. A small chip on the apex forming into a crack that splits the blade is probably so rare as to be statistically insignificant.


I’ve seen blades crack. Many of them. Never once have I seen a blade crack due to apex damage. Seen plenty of them crack from thumb studs being pressed in, or relief cuts being the start, or opening hole, etc. Never once a crack at the apex.

Take that for what it’s worth. I think you should worry more about a meteor falling on your head before a chip in your edge forming a large crack.
I agree.

We know that fixing a rolled edge will result in fatigued steel, and it can be demonstrated with ease. Chips turning into cracks is extremely low probability, and more theoretical.

Either way, it's better to get a knife steel that resists both. There are plenty that will work for the average Joe, and a few that work well for people who truly need it.
Karl_H
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Re: Golden Colorado Heat Treat

#26

Post by Karl_H »

Snacktime wrote:
Sat May 16, 2020 10:57 am
Lots of scraping lately, stripping romex and kitchen duty cutting on ceramic plates.

I sharpen on 300, step to 600 and then 1000. Stromp a couple times to finish/clean up.

Only two of my knives are chipping, I constantly change what I carry. I have 5-6 knives I rotate through and carry at work. Going back to my hole and going to pull another nib rex45 out of the box, take factory edge off and test this week.
It seems to me that the most likely explanation is that the factory edge geometry is probably just too thin for your intended use. If you use your knives for scraping, stripping, and cutting on ceramic plates, you should probably make your edge bevels more obtuse. I don't use my pocket knives for these things, so I don't really know what the optimal edge geometry might be for you.

Or if you want to keep using the factory grind angles, then stop using your thinly ground knives for the applications that are causing chipping and rolling. Get other tools that are better suited to those jobs (scrapers, wire strippers, cable cutters, serrated steak knives, etc). Rather than rotating 5-6 knives, you might be better off with a more specialized quiver of tools that have different edge geometries.

Based on the information provided, I don't really have any reason to suspect there is a problem with the heat treatments. Rather than focusing in the heat treatment, I suggest focusing on the things that you can control (use and edge geometry).
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kennethsime
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Re: Golden Colorado Heat Treat

#27

Post by kennethsime »

I've managed to chip both of my Rex 45 knives at this point, both with factory edges, but I definitely blame myself in both cases, rather than the factory. In each case I struck metal with the edge, leading to the chip. One of these days I'll order some CBN stones for the sharpmaker, lol.
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