CPM SPY27 Experiments - Toughness, corrosion resistance, etc

[Larrin]

I did a range of experiments on SPY27 including heat treatment response, corrosion resistance, toughness, and micrographs. And a comparison with previous predictions of what the properties would be. https://knifesteelnerds.com/2020/03...ents-toughness-corrosion-resistance-and-more/

 

[Revolverrodger]

Thanks for the testing
So it performs roughly like s35vn but is significantly more expensive

 

[Eli Chaps]

Excellent follow-up Larrin. Thank you.

 

[Larrin]

Thanks for the testing
So it performs roughly like s35vn but is significantly more expensive

The cost of the steel itself is probably only marginally different than S35VN, perhaps slightly more expensive due to the cost of cobalt. However, the price of knives from Spyderco may be a different story. I haven't looked at the prices much. There may have been some development costs and exclusivity that is factored into the cost of the knives.

 

[marrenmiller]

Nice article, Larrin.

Looks like a steel that BBB will appreciate quite a bit, but in a production setting I'm still not convinced there's anything to be excited about. We'll have to see how well Spyderco does with it.

 

[dirc]

I wonder if they just overdid the cobalt % - since it seems very similar to s35vn overall - perhaps a bit more attainable hardness as a bonus?
Or maybe they'll get to skip cryo and save some costs on that end?

in any case, I'm sure spyderco marketing will make the most of it, since it's shiny and new and 'exclusive'

 

[Larrin]

I wonder if they just overdid the cobalt % - since it seems very similar to s35vn overall - perhaps a bit more attainable hardness as a bonus?
Or maybe they'll get to skip cryo and save some costs on that end?

in any case, I'm sure spyderco marketing will make the most of it, since it's shiny and new and 'exclusive'

Whether they overdid cobalt or not probably depends on what the end goal was. 1.5% doesn't seem like a huge amount. It could be that hardness is marginally higher for certain heat treatments, especially without cryo, as you said.

 

[Larrin]

Nice article, Larrin.

Looks like a steel that BBB will appreciate quite a bit, but in a production setting I'm still not convinced there's anything to be excited about. We'll have to see how well Spyderco does with it.

62 Rc would go a ways toward building excitement. I wonder how they will heat treat it.

 

[marrenmiller]

62 Rc would go a ways toward building excitement. I wonder how they will heat treat it.

I would wonder how differently it would behave to S35VN at a similar hardness

 

[Larrin]

I would wonder how differently it would behave to S35VN at a similar hardness

They would probably be rather similar, but since Spyderco hasn’t had 62 Rc S35VN knives it would offer some differentiation for SPY27 to provide higher hardness.