Larrin Thomas also has a book Knife Engineering: Steel, Heat Treating, and Geometry https://www.amazon.com/dp/B08D4P9D95/ref=cm_sw_r_cp_api_i_fE7HFb3YFHTVD. Much of the information is available on his website, but it’s formatted here in a logical order. It’s quite good, I have a copy and have been working my way through it. It is very nerdy though lol.
Break grain is actually not accurate to grain size btw. I highly suggest knife engineering https://www.amazon.com/Knife-Engineering-Steel-Treating-Geometry/dp/B08D4P9D95
Great void and will have all your answers in it.
What kind of steel is it?
Tbf, metallurgy and blade design have a lot of science and engineering involved in them. This book is pretty great for anyone interested in that side of things, easy read: https://www.amazon.com/Knife-Engineering-Steel-Treating-Geometry/dp/B08D4P9D95
That said, this particular piece looks like someone just had some fun with a CNC machine and some metal. It would be a big stretch to call it engineering.
a book called Knife Engineering
https://www.amazon.com/Knife-Engineering-Steel-Treating-Geometry/dp/B08D4P9D95
So much to unpack here...
> After buying a couple of knives I've now been reading into all sorts of metal types.
Unless you've been reading Larrin Thomas or Roman Landes you've probably been wasting your time here.
https://www.amazon.com/Knife-Engineering-Steel-Treating-Geometry/dp/B08D4P9D95
https://www.amazon.com/gp/product/3938711043
> Trying to find the best knife steel.
To an extent this is going to be application specific. But as a general rule you will want to thoroughly understand what Roman Landes has written on this topic. If you don't speak German, you'll need to read the summary written by Larrin Thomas.
> Then cv20 won it over 390 because of the way they make the knives in my mind said it was better.
These steels are identical in composition. While there certainly can be differences in production techniques at the foundry I have never seen anything to support these claims. Heat treatment by the knife maker will have a huge difference in how both of these steels will behave, so any claims that one steel is better than the other are almost certainly a function of the heat treatment, not the foundry.
> For over all strength m4 seemed the way to go
Of these steels, arguably it is. However, all of these steels fall into the category of low toughness.
[m4] has little to no corrsion resistance
This is absolutely false. Corrosion resistance is vastly superior to high carbon steels like 1095.
Unless you are regularly around salt water (or you sweat heavily on the knife) corrosion simply isn't going to be an issue.
> Then cv20 won it over 390 because of the way they make the knives in my mind said it was better.
This is the Ford vs. Chevy argument
> So 20 vs 35, the 20 holds an edge more so more life
Edge retention is vastly more a function of heat treatment and how you sharpen the knife than it is steel type.
> but isn't as tough and is more difficult to sharpen.
There is no significant difference in sharpening as a function of steel type. You will see a greater difference in terms of how the steels were hardened.
And none of these steels are difficult to sharpen with the appropriate stones, regardless of hardness.
> There's a company called sandrin that has patented the rights to the metal alloy of it so it isn't brittle
What they are claiming is their alloy is less brittle than other tungsten alloys. Their alloy is still less tough and more brittle than any of the other steels discussed here.
> and is far harder than any steel here.
And as such this is one case where you may find the steel difficult to sharpen regardless of your stone choice.
I'm hoping someone will pick up on my hints this Christmas about this: Knife Engineering: Steel, Heat Treating, and Geometry https://www.amazon.com/dp/B08D4P9D95/ref=cm_sw_r_u_apa_fabt1_DlWVFbFW1NZ6S
> I love blades and sharpening them and such but I an really not knowledgeable about steel.
Well I've got a treat for you:
Much if the same content is available in dead tree form:
https://www.amazon.com/Knife-Engineering-Steel-Treating-Geometry/dp/B08D4P9D95
But I can also save you a whole lot of trouble here. Forget worrying about steel type and concentrate on geometry. You'll see far more benefit from optimizing geometry than you will steel type.
To add to this, Magnacut was designed by Dr. Larrin Thomas. He's literally written a book on knife steels. The man has more experience with knife steels than any person on the planet. Magnacut is his take on a near perfect pocket knife steel.
Little more about Magnacut:
https://knifesteelnerds.com/2021/03/25/cpm-magnacut/
Here's a link to his book:
https://www.amazon.com/Knife-Engineering-Steel-Treating-Geometry/dp/B08D4P9D95
This site is run by a metallurgist. He also wrote a book.
The numbers in that guide were pulled entirely out of someone's ass.
If you want to actually learn about steel and its properties then you'll need to do a bit of reading:
https://www.amazon.com/Knife-Engineering-Steel-Treating-Geometry/dp/B08D4P9D95
Another reality far less talked about is geometry and sharpening. A $10 knife with a thin grind and a well-finished edge can easily out-cut a $200 knife with the factory edge.
I think this is the one I've seen recommended most: https://www.amazon.com/dp/B08D4P9D95/
Definitely Knife Engineering—-it goes over heat treat, blade geometry, steel composition and more.
Knife Engineering: Steel, Heat Treating, and Geometry https://www.amazon.com/dp/B08D4P9D95/ref=cm_sw_r_cp_api_glt_fabc_9JMWCKDJHHH7Y7EZMPEZ
Get the book Knife Engineering ! I have found myself leaned against random walls reading this. I can't get enough of it.
https://www.amazon.com/Knife-Engineering-Steel-Treating-Geometry/dp/B08D4P9D95
Not much on history, but great on the working