cryo-ed spyderco

[troy_mclure]

2ridgebacks offered to cryo a spyderco atlantic salt for me to test out.

he recommended it be sharpened afterwards for best effect, so i sent it off to spyderco.

there was no change in the appearance of the knife, and the handle seemed to not be affected.

i currently own 9 of the salt series knives and use them for work as a commercial diver.

i use them for cutting poly and Marline rope on deck, and cutting everything from rope to shrimp net.

i have put this knife thru hell since i got it back, testing just how durable the cryo process has made it.

its been used 4 times as heavily, and cut crap i normally wouldn't, like 1/8" ss wire, and heavy electrical wire.

so far the knife is still extremely sharp, if not quite factory edged.

i would never have expected the edge to last so long, especially considering the abuse i put it thru.


ill be having more knives put thru this process.

 

[geauxshootin]

I have a knife he did as well and it has held it's edge very well!

 

[rcm192]

anyone ever hear of this process being used for firearms too? ive seen these guys a bunch of times at the gunshows. was kinda skeptical, just wondering...

 

[2ridgebacks]

2ridgebacks offered to cryo a spyderco atlantic salt for me to test out.

he recommended it be sharpened afterwards for best effect, so i sent it off to spyderco.

there was no change in the appearance of the knife, and the handle seemed to not be affected.

i currently own 9 of the salt series knives and use them for work as a commercial diver.

i use them for cutting poly and Marline rope on deck, and cutting everything from rope to shrimp net.

i have put this knife thru hell since i got it back, testing just how durable the cryo process has made it.

its been used 4 times as heavily, and cut crap i normally wouldn't, like 1/8" ss wire, and heavy electrical wire.

so far the knife is still extremely sharp, if not quite factory edged.

i would never have expected the edge to last so long, especially considering the abuse i put it thru.


ill be having more knives put thru this process.

I am glad to hear that your knife is working so well for you, I am also glad you are putting it threw some hard tests, that was exactly what i was looking for. I asked for your help, because I had read one of your posts that talked about the fact that you use these knives on a daily basis. This is valuable to me because in order for someone to fully realize the difference cryogenic processing makes one must first have a very good idea of how the item performs before the treatment. Thankfully even those who do not know exactly how long their knife normally stays sharp can still tell a big difference in a knife that I have processed. Thanks again

 

[2ridgebacks]

anyone ever hear of this process being used for firearms too? ive seen these guys a bunch of times at the gunshows. was kinda skeptical, just wondering...

PM sent

 

[troy_mclure]

finally killed the edge on the knife.

it took 3 hours of cutting thru several shrimp nets(that were wrapped around sub sea valves).

the next diver up killed his brand new spyderco in about 50 mins.

the edge is still there, but its not as sharp as i need it to be, so off to spyderco it goes.

 

[JBE]

Are you using plain-edged or serrated edge Salts?

 

[2ridgebacks]

finally killed the edge on the knife.

it took 3 hours of cutting thru several shrimp nets(that were wrapped around sub sea valves).

the next diver up killed his brand new spyderco in about 50 mins.

the edge is still there, but its not as sharp as i need it to be, so off to spyderco it goes.

Amazing, you posted the first update about this knife on Jan 8th and you had already put it threw a lot of abuse at that time. Now 4 months later you finally wore out the edge, that is some serious use and a great testimonial about cryogenic processing. Bladed Steel items are probably the best use of cryogenic processing and it is well known in the industrial tool, bit, die and cutting tool industries. Thanks Troy for your help in testing my process, I am very happy you had such great results and you should see the same results again when it comes back from sharpening.

The blade is a serrated edge by the way.

 

[troy_mclure]

always serrated, cuts rope and line 1000x better than a plain edg.

 

[2ridgebacks]

Question for the vendor...

One assumes this cryo process gives the blade steel some sort of properties that help maintain the edge? Please explain further, keeping in mind that AUS8 has much different properties than, say, D2.

Also, if I was to have an EDC knife done by this process, would I be able to "touch up" (i.e., maintain) the edge with my normal sharpening tool, which is a Spyderco Sharpmaker.

What about the knife scales? Do you put the entire knife through the process?

.

There are a number of things that happen to all ferrous steels during cryogenic processing. First the transformation of retained Austenite to Martensite is completed to 98% or so, this is a higher percentage than heat treating alone. The higher percentage of Martensite is one factor that improves wear resistance and toughness. Second is a evening of the crystalline structure, as the metal is cooled it condenses, the metal matrix is evened out and weak points are removed. This also allows the micro-surface of the metal to flatten out which is the reason moving parts in knifes and firearms smoothen and the reason that processed blades are able to be sharpened to a keener edge. In steel alloys, eta carbides are formed during the 24hr soak and are dependent on the alloying metal Ex. Ferrous Stainless steels may build Chromium carbides, these carbides in addition to the high martensite percentage help in edge retention and blade toughness. Another benefit science knows about is the relief of residual stress, During the forging, milling, or other manufacturing processes stresses are built in to the metal and can cause failures. When the metal is brought to -300f temps the metal "relaxes" and the stresses imposed during manufacturing are relieved. This also helps to prevent failures within the metal. The last thing is a factor that science does not yet know about, we know that there is something else going on during the process as unexplained benefits to metals with no Austenite are realized but the reasons have not been identified to this point.

The differences in the many ferrous steels available do not translate to vastly different results in this process, The differences in AUS 8, ATS 34, D2, A2 ect. do not substantially affect the results of the process as the reasons for the benefits do not change. Tool steels do seem to respond the best to deep cryogenic processing but not by a substantial amount. Even Non-ferrous metals like Aluminum and Titanium benefit from the evening of the crystalline structure, and relief of residual stresses.

After processing you can sharpen the knife as you normally would, the process will not change the looks of the metal either.

As far a scales, most will do fine, I descend at ½ degree per min. This rate is slow enough to avoid thermal shock in most materials. I prefer to process the blade by its self but in many cases there is no option to remove the handle. In the case of this Spyderco I processed the entire knife as the handle could not be removed. The Molecular structure of the polymer will also even out the same way the crystalline structure of the metal does, so there is a benefit for the polymers as well. Some of the lower quality plastics crack during the process but the higher quality polymers, composites, as well as wood and any metal will come out fine.

I hope I have adequately answered your questions, feel free to ask more if needed.

 

[troy_mclure]

Another update. Work slowed down a bit, and I didn't use the knife untill recently. I have the knife in rotation with others so they get sharpened as needed. A few weeks ago I went thru 2 hacksaw blades and a on treated Spyderco cutting dozens of feet of 2" and 3" rope from a boats prop. The treated spyderco(3rd sharpening from Spyderco) was able to finish up the last of the rope with ease. It's still nice and sharp after cutting about 6" of rope.
On a side note I have had 2 other salts replaced due to slack blades from loss of pin tension. A fairly common issue with the salt series. The treated knife gets more use and still hasn't failed. I don't know if the pins were positively affected or not.

 

[762NATO]

What does "cryoed" mean?

 

[Bosco]

What does "cryoed" mean?

http://en.wikipedia.org/wiki/Cryopreservation

I wish I would have gotten my BS spyderco done. Thought there was gonna be a special for em for $5 when they came in but nothing ever happened from it

 

[LACamper]

Just curious. What happens if you take a spyderco and drop it into a tank of liquid nitrogen for 24 hours. Not gradually, just toss it in. Would there be any benefit? Or damage?