Tell Me your thoughts on CPM 15v

Twindog said:
I think K390 is right in the sweet spot for highly wear-resistant steels that are reasonably tough.
Click to expand...
I agree. K390 is a fantastic steel if you want high wear resistance and more toughness. I have a few knives in 10V and K390, they are great steels, but not for hard use. Good for small fixed blades and folders, but for a knife that might see a chance of hard use, I will stick with tougher steels. I love 3V for its all around attributes. Perfect outdoors steel. It definitely has enough edge holding for me, and is easy to sharpen. 15V would be fun to try, for a knife user, but I personally don't think it would be something I'd pursue more than once. IMO
 
I still have the 15V 70rc chomper. At any rate, from my ht calculation - 15V 70rc should has toughness similar to S90V 65rc. But hey, I could be quite wrong for lower hardness. 15V 70rc 4" blade 3/32-1/8" thick, 0.01"BET 15dps should be fine for a pressure/slice cutting knife.

Here is an old video of the 15V chomper


ViBCKQ3.jpg
 
Natlek said:
I say no one on this world can HT ANY steel to get 130 % better blade then HT protocol given by manufacturer..................
Click to expand...
https://www.bladeforums.com/threads/bcmw-cpm-15v-70rc-chomper.1481533/

ETA: Bluntcut himself posted :eek::D
TheEdge01 said:
I’ve been leary about trying ZDP-189 due to low toughness which means it is prone to chipping or snapping. Well, CPM15V is yet another one I will avoid as well.
Click to expand...
Not saying ZDP is tough, but not as brittle as thought of. Haven’t done any testing like Twindog, ...https://www.bladeforums.com/threads/zdp-189-endura-initial-impressions.1543063/
 
Natlek said:
Are you kidding me ? What is then incorrect in my post ? So do you have same example of your claim ? 1350 vs 2950 cut ? Relevant one .Not on tube , on tube rust even most stainless steel :D
Click to expand...

I'm not a knifemaker but I do heat treating for knife makers on various steel but mainly high alloy steel like 3V, xhp, m390 etc. with impressive result.

I will say heat treating can make steel behave over 10 times differently even at the same hardness especially for knife edge application.
 
On topic, I wouldn't use 15V to make knife even if it free. Far too much alloy to hold a good knife edge and would be not very much tougher than tungsten carbide. This stuff seems to work only with super wide geometry like industrial blade.
 
shqxk said:
I'm not a knifemaker but I do heat treating for knife makers on various steel but mainly high alloy steel like 3V, xhp, m390 etc. with impressive result.

I will say heat treating can make steel behave over 10 times differently even at the same hardness especially for knife edge application.
Click to expand...
Can you give us all that impressive result translate in numbers ? I like to compare them with factory HT numbers ?
 
Natlek said:
Can you give us all that impressive result translate in numbers ? I like to compare them with factory HT numbers ?
Click to expand...
Manufacturer suggested heat treats are NOT knife specific. Many alloys are made for other industries and as such their heat treats tailor to the industry it is designed for.

Heat treating to get specific qualities out of an alloy for a KNIFE are often not the same heat treat as suggested by the manufacturer.
 
Natlek said:
Can you give us all that impressive result translate in numbers ? I like to compare them with factory HT numbers ?
Click to expand...

Heat treat does make a huge difference -- or it can. Check out Juha's thread on how differences in heat treat -- even to the same 60 Rc -- can make a large difference in grain size and toughness (resistance to chipping and breaking).

it-vs-gs-png.725822

All the data points are for the same steel at 60Rc. You can see the range in toughness, from almost 80 J/cm2 to less than 20 J/cm2.

That chart is from this thread:
https://www.bladeforums.com/threads/carbon-steel-blades-and-grain-size.1503062/

You might also want to read Bluntcut's epic heat treating and testing thread(s). He has done amazing work, and he has shared that work with the rest of us.
 
shqxk said:
On topic, I wouldn't use 15V to make knife even if it free. Far too much alloy to hold a good knife edge and would be not very much tougher than tungsten carbide. This stuff seems to work only with super wide geometry like industrial blade.
Click to expand...
How does Luongs' (Bluntcut) video posted above compare to your views on the alloy?

He does have one chip, but it doesn't seem to be as brittle as you stated, especially for 70hrc.
 
Twindog said:
Heat treat does make a huge difference -- or it can. Check out Juha's thread on how differences in heat treat -- even to the same 60 Rc -- can make a large difference in grain size and toughness (resistance to chipping and breaking).

it-vs-gs-png.725822

All the data points are for the same steel at 60Rc. You can see the range in toughness, from almost 80 J/cm2 to less than 20 J/cm2.

That chart is from this thread:
https://www.bladeforums.com/threads/carbon-steel-blades-and-grain-size.1503062/

You might also want to read Bluntcut's epic heat treating and testing thread(s). He has done amazing work, and he has shared that work with the rest of us.
Click to expand...
This is NOT conventional 1080 steel to play with size of carbides ! This is CPM 15V powder metal tool steel we talk about ! This is not a steel that you HT in backyard barn . I wonder how many knife maker have equipment to HT this steel ??
Now , this is protocol for HT this steel from manufacturer , there are several options described how to HT this steel for max.wear resistance or max.toughness........So , please find that knife maker who can get at least 30% better performance WITH his SPECIAL heat treatment process , but to do not lose one attribute to get another one ...........toughness/wear ! I don't even want to think about difference of 130% like that guy on You tube !
There was are reason why you don t see this steel in knife . And that is that it is brittle like glass and have HALF toughness of M2 Steel which is already almost no go for serious knife use ... I will no comment about bluntcut work .I will keep my opinion about his work for my self .
https://www.cartech.com/globalassets/datasheet-pdfs/cpm_15v.pdf

http://www.crucible.com/PDFs/DataSheets2010/ds15Vv1 2010.pdf
 
Last edited:
I have one question for all of you who believe in special HT on powdered steel . Bohler-Uddeholm in addition to all listed field of applications for M390 steel , say that this steel is good for knife too .So , my question is why they not give a special HT for that application. I don t think that they do not know or do not care for that ? Do not you think that they know THAT steel a little bit better then everyone on this world , and if there is some better way to HT M390 for knife they will recommend it to users ?
 
Knife steels can be heat treated to maximize stain resistance, toughness, wear resistance or strength. Sometimes, the heat treating has to be spot on. I bought a new axe a while back with an acute edge that was designed to make it a better chopper. The maker used an alloyed steel to be able to get to the right hardness and toughness to support the thin edge.

Mine chipped badly when I put it to use clearing a trail through the rainforest. I sent macro photos of the axe head to the manufacturer. A top company official got right back to me. He acknowledged that the heat treat was obviously bad on that axe, and he suspected it was heat treated during a time when the company was changing its heat treating protocol.

Here's what he said: "...…the nature of the thinner but much sharper 25 degree flat grind must be quenched immediately when it reaches the proper heating temp and time frame.* Even a second could cause the thin edge of the blade to cool too quickly before quench."

Heat treats can be that sensitive.

When S30V came out, a lot of people experienced chipping. The problem was traced back to a problem with the heat treat where the blades didn't get quenched quickly enough. This on a high-end powder steel.

I indicated earlier how some knife makers can produce more elaborate, high-end heat treats that are too labor- and time-intensive for manufacturers to use. Read about Ed Fowler's heat treat for his best 52100. No manufacturer could follow that recipe and still sell knives at a profit.

A 3V chopper that I received was chipping on me when it shouldn't have. A well-known knife maker tested it and told me the steel was poorly heat treated. Bluntcut redid the heat treat, and the knife chops much better without chipping.

Heat treats matter.
 
Natlek said:
I have one question for all of you who believe in special HT on powdered steel . Bohler-Uddeholm in addition to all listed field of applications for M390 steel , say that this steel is good for knife too .So , my question is why they not give a special HT for that application. I don t think that they do not know or do not care for that ? Do not you think that they know THAT steel a little bit better then everyone on this world , and if there is some better way to HT M390 for knife they will recommend it to users ?
Click to expand...
Different heat treats provide different results. I'm not an expert on heat treating, but I feel I have a decent understanding of how it works.

The suggested heat treat from the manufacturer is a starting point. Not the end all be all of what can be achieved with the steel.

Custom heat treating to bring out specific characteristics isn't a fairy tale, and yes, heat treats exist that deviate from the manufacturers suggestion that provide better performance as a knife.
 
I don't recall any steel company that provides their "factory recommended" HT and then another for "cutlery". There are a few companies that DO provide a cutlery HT, but their steels are specifically made for cutlery. Even then....we can change the recommended HT of cutlery steel to make it better.
Most of the PM steels are made for other applications, and the HT for such is tailored for that application. The knife industry really is small for these companies, so I can understand why they don't. But those of us who like to "dig in the dirt" about this stuff, we know how to tweak an "industrial" heat treatment for one that better suites our purposes.
 
Twindog said:
Knife steels can be heat treated to maximize stain resistance, toughness, wear resistance or strength. Sometimes, the heat treating has to be spot on.
A 3V chopper that I received was chipping on me when it shouldn't have. A well-known knife maker tested it and told me the steel was poorly heat treated. Bluntcut redid the heat treat, and the knife chops much better without chipping.

Heat treats matter.
Click to expand...
Exactly !
But you do not get 50-100% better blade then Factory HT recipe for same
characteristics .

Well ,we don t talk about BAD HT ...........The assumption is that HT is done properly .............
 
I think you misunderstand the result of Pavol's testing :D
130% difference does not come from HT alone....there are some geometric differences between the knives ;)
 
Twindog said:
I indicated earlier how some knife makers can produce more elaborate, high-end heat treats that are too labor- and time-intensive for manufacturers to use. Read about Ed Fowler's heat treat for his best 52100. No manufacturer could follow that recipe and still sell knives at a profit.
Click to expand...
I read and learn a lot , but not on forums . Now , you read this about magic HT ......... https://www.bladeforums.com/threads/time-from-quench-to-temper.744224/#post-8251341
And this too if you like ......................... https://www.bladeforums.com/threads/liquid-nitrogen-vs-dry-ice.1540810/page-2
 
You must log in or register to reply here.
Back
Top