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http://www.nsm-ny.com/index.cfm?fuseaction=page.display&page_id=27
Why haven't I ever heard of CPM 4V ??? [ not V4 ]
Why haven't I ever heard of CPM 4V ??? [ not V4 ]
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Cpm v4
- Thread starter mete
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The specs look good, interesting...
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interestign and i had heard about it a bit but its not what i wanted to see done to the 3v mix
i wanted the V dropped to 2 Nb added to ofset a bit and a hair more carbon
i wanted the V dropped to 2 Nb added to ofset a bit and a hair more carbon
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PD1 from car tec seems to be what im looking for
Stacy E. Apelt - Bladesmith
ilmarinen - MODERATOR
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That chart shows why I like CPM-S35VN so much. Only CPM-M4 has a higher W/T rating in both fields. The near evenness of the two ratings is a plus, as neither one is an issue over the other.
If the wear resistance of CPM-4V is greater than CPM-S35VN, it should be a superb hard use blade steel. I wonder how it works and finishes?
If the wear resistance of CPM-4V is greater than CPM-S35VN, it should be a superb hard use blade steel. I wonder how it works and finishes?
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just as a note i hate graphs like this as they dont tell you what hardness any of the steeels are
like the book spec for 3v is 58-59 but its way better ballanced in knives at 61-62 (the ware woudl be higher then the graph also then)
like the book spec for 3v is 58-59 but its way better ballanced in knives at 61-62 (the ware woudl be higher then the graph also then)
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As a former analytical chemist, I take graphing seriously as it is an important tool of the trade. The problem with charts such as this is that the vertical axis is not defined by specific units. It appears to compare the relative wear resistance and toughness in some unspecified way. This can lead to misinterpretation or worse, misuse.
One way to misuse this data is to associate these relative and unspecified values with actual specific properties of the steel in question. Comparing CPM-S90V to O1, we see a 7.5x advantage in wear resistance over the O1. Does this mean that an O1 blade would require sharpening 7.5 times as frequently as the CPM-S90V? We have no way of knowing because the chart does not specify any test conditions(like Hardness, as pointed out by Butch) or measurement techniques.
While I enjoy having data available from the steel companies, it is important to differentiate between scientific data and marketing materials.
I'll get off my soapbox now. I too am looking forward to seeing what knifemakers can do with this interesting new alloy. -Doug
One way to misuse this data is to associate these relative and unspecified values with actual specific properties of the steel in question. Comparing CPM-S90V to O1, we see a 7.5x advantage in wear resistance over the O1. Does this mean that an O1 blade would require sharpening 7.5 times as frequently as the CPM-S90V? We have no way of knowing because the chart does not specify any test conditions(like Hardness, as pointed out by Butch) or measurement techniques.
While I enjoy having data available from the steel companies, it is important to differentiate between scientific data and marketing materials.
I'll get off my soapbox now. I too am looking forward to seeing what knifemakers can do with this interesting new alloy. -Doug
Stacy E. Apelt - Bladesmith
ilmarinen - MODERATOR
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With proper geometry and HT, it can be a very good steel. Hundreds of million knives are made with 440C.
Stacy E. Apelt - Bladesmith
ilmarinen - MODERATOR
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Ahh, I see. Yes the CPM-154 graph seems a tad low.
The difference is what Lloyd was saying. 440C has an as-quenched hardness of around 59, and CPM-154 has an as quenched hardness of up to 63 ( depending on the quench). The finer and more even grains in the CPM steel are also an advantage.
These charts are a good starting point, but a lot farther study is needed before picking a steel.
440C makes a good general use knife in the Rc56 range. CPM-154 makes a good knife in the Rc 58-59 range. Not apples to apples.
One more fly in the ointment:
These type charts are often cobbled together from a variety of text book info. Most of that info has nothing to do with knives. Some of these tests are done with different equipment, and are not a true corollary to each other.
Sure, the steels listed can make a great knife, but a test done on a 1" round bar has little to do with how a very fine edge will hold up in cutting up an elk.
The difference is what Lloyd was saying. 440C has an as-quenched hardness of around 59, and CPM-154 has an as quenched hardness of up to 63 ( depending on the quench). The finer and more even grains in the CPM steel are also an advantage.
These charts are a good starting point, but a lot farther study is needed before picking a steel.
440C makes a good general use knife in the Rc56 range. CPM-154 makes a good knife in the Rc 58-59 range. Not apples to apples.
One more fly in the ointment:
These type charts are often cobbled together from a variety of text book info. Most of that info has nothing to do with knives. Some of these tests are done with different equipment, and are not a true corollary to each other.
Sure, the steels listed can make a great knife, but a test done on a 1" round bar has little to do with how a very fine edge will hold up in cutting up an elk.