Spyderco Forums

I was reading some info on tool steels and I came across this, there was a stainless tool steel called "CPM T440V" which was enriched with a lot of vanadium. Then I looked at an old thread that said Spyderco once produced black coated Military folders which had a stamp on them that said "CPM T440V". Is this the blade steel that was used on that specific knife, and, has Spyderco ever used this steel on other knives? I read that it has a good balance between the wear resistance one expects from tool steel alloys, combined with the corrosion-resistance of stainless steels.

Are you talking about S60v?

Check out the chart.

http://www.spyderco.com/edge-u-cation/index.php?item=3

440V was used in a number of the early Natives, I have one in SE, it is the same as s60v apparently.

The names changed. Used to be 440V then changed to S60V. I didn't care for the steel that much. Needed to be far too soft to have a long lasting edge. Others liked it.

No, he's talking about a pre-production Military that was marked CPM-T440V. Here's a link to a thread with photos. Don't there were any actual production Military, or any other production Spyderco, ever used it.

The Deacon wrote:No, he's talking about a pre-production Military that was marked CPM-T440V. Here's a link to a thread with photos. Don't there were any actual production Military, or any other production Spyderco, ever used it.

There's not a difference between T440V, CPM 440V, and S60V, is there?

My sterile one was marked CPM-440V...no "T'...

Bodog wrote:

The Deacon wrote:No, he's talking about a pre-production Military that was marked CPM-T440V. Here's a link to a thread with photos. Don't there were any actual production Military, or any other production Spyderco, ever used it.

There's not a difference between T440V, CPM 440V, and S60V, is there?

I don't know, but it is possible. I'd guess there's someone at Spyderco, and am sure there's someone from Crucible, who does.

Stuart Ackerman wrote:My sterile one was marked CPM-440V...no "T'...

CPM 440V was definitely used on production versions of the Military, and on the Native. OTOH, Recoil's black bladed Military is the only one I've ever seen that's marked CPM T4440V.

I have a 440v full SE millie.

The Deacon wrote:

Bodog wrote:

The Deacon wrote:No, he's talking about a pre-production Military that was marked CPM-T440V. Here's a link to a thread with photos. Don't there were any actual production Military, or any other production Spyderco, ever used it.

There's not a difference between T440V, CPM 440V, and S60V, is there?

I don't know, but it is possible. I'd guess there's someone at Spyderco, and am sure there's someone from Crucible, who does.

Stuart Ackerman wrote:My sterile one was marked CPM-440V...no "T'...

CPM 440V was definitely used on production versions of the Military, and on the Native. OTOH, Recoil's black bladed Military is the only one I've ever seen that's marked CPM T4440V.

I'm pretty sure it's the same. I read some stuff from the 90's and it said crucible originally designated CPM440V as T-440V, T standing for type, and then fast forward they then removed the T and labeled it as CPM 440V, then S60V. CPM 440V changed to S60V around the same time they changed it from 420V to S90V. But that could be all wrong. It's not wise to trust anything on the interwebz without a firm, reliable source.

Yes, CPM 440V, T440V, CPM S60V all the same grade just different designations evolved over time. This was the first one with the CPM process with enough Chrome to be stain resistant. The problem early on was that is had a pretty low obtainable hardness. It was later tweaked a bit to help with that but about the same time CPM S90V was introduced as an upgrade. CPM S60V ( now the correct designation) slowly faded out as CPM S90V replaced it. S60 means 6 % V and 9 is 9%V as we all now know. There are plans to re-intoduce CPM S60v since some makers have been asking for it. This was the first CPM grade I used and made a lot of utility hunters and fillet knives with it. It would be interesting to go back and use some of it and work up some better heat treats if it becomes available to us. Phil

Phil Wilson wrote:Yes, CPM 440V, T440V, CPM S60V all the same grade just different designations evolved over time. This was the first one with the CPM process with enough Chrome to be stain resistant. The problem early on was that is had a pretty low obtainable hardness. It was later tweaked a bit to help with that but about the same time CPM S90V was introduced as an upgrade. CPM S60V ( now the correct designation) slowly faded out as CPM S90V replaced it. S60 means 6 % V and 9 is 9%V as we all now know. There are plans to re-intoduce CPM S60v since some makers have been asking for it. This was the first CPM grade I used and made a lot of utility hunters and fillet knives with it. It would be interesting to go back and use some of it and work up some better heat treats if it becomes available to us. Phil

Pardon the silly questions, but where did the 440 and the 420 come from in the designations? Are they 440 with a lot of vanadium and 420 with a lot of vanadium? If so, why will S90V take a higher hardness than S60V?

Phil Wilson wrote:Yes, CPM 440V, T440V, CPM S60V all the same grade just different designations evolved over time. This was the first one with the CPM process with enough Chrome to be stain resistant. The problem early on was that is had a pretty low obtainable hardness. It was later tweaked a bit to help with that but about the same time CPM S90V was introduced as an upgrade. CPM S60V ( now the correct designation) slowly faded out as CPM S90V replaced it. S60 means 6 % V and 9 is 9%V as we all now know. There are plans to re-intoduce CPM S60v since some makers have been asking for it. This was the first CPM grade I used and made a lot of utility hunters and fillet knives with it. It would be interesting to go back and use some of it and work up some better heat treats if it becomes available to us. Phil

Phil, would you say Vanadis 6 could essentially be a significantly harder S60V with less stain resistance?

Dodog, yes even though I don't have experience with Vanidis 6 the chemistry would indicate less stain resistance and an end hardness of around RC 61 would be higher than CPM S60V on average. S60V was more like 58/59.

Doc, The CPM 440V came from the basic 440C chemistry but with 6% vanadium. The CPM 420v came from the basic 420 chemistry 12 to 14 % chrome but with 9% vanadium. The newer S60V and S90V designations are less confusing. The S stands for stainless. That separates it from CPM 10V where the S is not there since it has only 5% chrome. The convention is still not truly consistent since CPM 154 is stain resistant but the S is left out?? Phil