HSS High Cobalt Steel

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Hello! I want ask is anybody here forge a custom knife from 5% Cobalt or 10% Cobalt lathe knife? If yes please can you say is any good? Because i have alot lathe steel laying around. Thanks

 

[Templehound]

I am a bit wondering why don't you google it?.....

The object of the heat treating or hardening operation is to transform a fully annealed high-speed tool steel consisting mainly of ferrite (iron) and alloy carbides into a hardened and tempered martensitic structure having carbides that provide the cutting tool properties.

The recommended heat treatment (HT) process is as follow: Stress relieve at 600°C - 650°C (1110°F - 1200°F) for one to two hours. Heat to between 1190°C and 1230°C (2170°F - 2245°F). Soak at temperature for minimum 80 seconds and maximum 150 seconds, depending on heating temperature and cross-sectional area of tool.

.....but!.....look at the temperatures, if your oven brings it you will still have the problem of atmosphere(150 seconds without vakuum will/can burn it to none
https://www.tandfonline.com/doi/abs/10.1179/1749514813Z.00000000070?journalCode=yhse20

and most of HSS steels are not making a good knife blade at all.
there are a few Hss alloys you can make a knife blade but they're not worth it.....imho.
Htreating them costs a lot of energy(oven) and tools(grinding belts) and most Hss tools are not strong on an edge with 20-40% ....
and .....and you don't know which of the numerous steels you have there....there are significant differences

Cheers

 

[Escort]

Thanks for reply. Cheers

 

[Natlek]

and most of HSS steels are not making a good knife blade at all.
there are a few Hss alloys you can make a knife blade but they're not worth it.....imho.

M2 , M35 and M42 HSS are not good for knife blade at all ? Are you serious ? I make so far maybe around 60 - 70 knives from them and I like them ! M42 on 68 HRC cut and hold edge like crazy !
This one is from M35 and I used it this year fishing season ,you have no idea how much use it see and it still cut and cut ...............

 

[Templehound]

Natlek, howdy.
Yes I am serious, it is my opinion, I said "most HSS steels" I didn't said all of them....
and I didn't said anything about M2, M35 and M45Hss do not make a good blade.
what I said was according to some unknown HSS scrap material
but I would not recommend making blades out of unknown HSS scrap material in the hope it is or could be M2 or another HSS suitable for knife blades.
would you?
so my opinion was only about unknown HSS scrap

.....but besides HSS scrap please don't get me wrong,
I should have written: " some make a good blade for somebody but to me they make not a great blade at all"...
..if you like those steels it is fine with me.
I tried M2 and I was not convinced, it is more expensive to work with(tools, belts, and HT) and its price itself, like most PM steels.
so for me as a full time maker they are inefficient enough.
to be honest....I didn't tried M35 and M45Hss

Conclusion
The development of super hard and carbide replacement high speed steels came from a long history of continuous improvement in high speed steel design and production. The improvements in steelmaking combined with the improved understanding of high speed steel alloy design led to a combination of high cobalt and optimized carbon content to maximize hardness. With the introduction of powder metallurgy it was possible to increase the vanadium content to offer a combination of very high wear resistance and hardness. These steels offer relatively low toughness when compared with many other knife steels, but offer excellent edge retention. The high cost of both purchasing these steels and producing knives out of them limits their usage to a relatively small number of knives. However, they provide specialized use cases for those that prefer maximum edge retention at the detriment of other properties.

more about this here:

https://knifesteelnerds.com/2019/12...ed-steels-maxamet-rex-121-and-more-explained/

so I am not questioning HSS for knife blades I am doubting unknown HSS scrap material

are we cool?....

nice Puukko by the way.

Cheers

 

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M2 , M35 and M42 HSS are not good for knife blade at all ? Are you serious ? I make so far maybe around 60 - 70 knives from them and I like them ! M42 on 68 HRC cut and hold edge like crazy !
This one is from M35 and I used it this year fishing season ,you have no idea how much use it see and it still cut and cut ...............

Thanks . Have a nice day and fishing

 

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I was asking because i want to make carving tool ... something like kiridashi out of Hss to maintain Edge Retention and Toughness over long period... and sharpen on belt grinder if needed...without losing tempering. Last night i ask Malanika (Daniel) ,he said it would be ok to try play with. I love exotic steel and experiment with new things.

 

[nmbarta]

You can make a lot of decent stuff out of unknown parts. It won't likely be perfect, but it will likely carve if you build it right. Build it and use it, then you can be the one to answer questions about it. People get to caught up numbers, just build it and use it, if it works for your application, that's all you need to know. I have a s35v pocket knife that a36 would probably out perform....it's garbage, doesn't mean s35v is garbage, it means the builder made a mistake.