115W8 German Metal Cutting Steel Test Blade| Cutting Through Nail and Mild Bar

J

joshiecole

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Apr 29, 2012
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I am always searching for steels capable of high hardness, high toughness steels and have recently been experimenting with 115W8, a German steel originally designed for cutting other metals. It is capable of very decent toughness even at 62HRC.

Here is a test blade I made being hammered through a 3mm nail and then cutting into 5mm or so round bar.

The test blade is 3.3mm (1/8th inch) thick at the spine.

[video=youtube;STT0fyOOaN8]https://www.youtube.com/watch?v=STT0fyOOaN8[/video]

[video=youtube;5sRLeEtBNLY]https://www.youtube.com/watch?v=5sRLeEtBNLY[/video]

Not a miracle steel (I don't believe in unobtainiums) but it's a fantastic choice if you're looking for high toughness at high hardness.
 
slamosam said:
Edge bevel inclusive angle and behind edge thickness?
Click to expand...

Unfortunately, putting an edge bevel on a piece of stock doesn't tell us much. It needs to be an actual knife.....not a sharpened bar. I would imagine a piece of aluminum with an edge bevel would cut thru a nail. Cut the bevels, take the edge down to .010", sharpen that, then repeat the nail cutting test.
 
It is not a single bevel on a piece of stock. You can only see the secondary edge because that was put on after the heat treat, whereas the primary bevel remained blackened.

It is about 0.5mm behind the edge and roughly 15 degrees per side (possibly very slightly larger due to unintentional convexing because of sharpening by hand). It's not kitchen knife geometry, but it's certainly not sharpened pry-bar either. :)
 
One spec sheet on that steel lists it as capable of 60hrc; it sounds interesting for sure. :thumbup::cool:
 
That steel should perform wonderfully at 64HRC even. Unfortunately, in the video, especially the beginning where it is held right up to the camera.....it looks like a piece of hardened bar stock was sharpened. Doesn't even look like it has a primary grind on it. You said it does, so I have no reason to doubt you, it just doesn't look like it when held up to the camera even in the close up shot. So does it have a full flat grind, or more of a saber grind? And stock thickness? We need this info for any meaningful results of any tests.

.5mm is only .020". I would expect any decently hardened steel with that geometry to cut thru a nail. Not trying to rain on your parade, but the test doesn't tell us much. If the stock is .090", and the blade is a FFG 1.3" tall, with a 15° edge per side, .010" measured at the edge shoulder.....that would be more info and more impressive. Cutting nails is a parlor trick mostly. It's done, not with excellent heat treatment or steel, but with heavy geometry. I'm still waiting for someone to do a nail cutting test on a super thin super hard nakiri or similiar knife! I have made a petty out of 1.2519 62HRC 0.063" stock, 15°ps, 0.005" behind the shoulder.....now THAT would be a nail cutting test! Not ABOUT to try it....don't ask!

115W8, 110WCrV5, these steels should best be used on thin slicers. That is where the alloying allows thin hard edges to stay sharp. And to that...the knife made from these steels should reflect such in their geometry. Sure, 115W8 is known to be a tough steel, but it's a waste of money, IMHO, to make a chopper out of 115W8 or 1.2519. I think of these steels as very very similiar to Blue steel....and indeed they are very close in composition.
 
Don't worry about raining on parades Stuart -- I like a good spirited chat, and one needs a good dose of healthy skepticism to inform meaningful debates. As I mentioned, the stock thickness is 1/8 of an inch.

I suspect you and I are looking to optimize our knives for slightly different purposes. I know you make extremely fine cutting edges. I am looking to make smallish utility knives that can withstand a pounding. This steel was recommended to me by the steel supplier precisely for this purpose.

You keep saying that any knife could hammer through nails or 5mm round bar but I have tried these tests with several other knives with very similar geometries and received much greater deformation.

I respect your opinion a great deal. I know you put in a lot of thought and contribute a lot to steel discussions on various different forums, but I do feel that this steel has a place for my application. My knives may are not as thin as some of yours, but they will happily slice garlic in the kitchen, and I find that the balance of high hardness and decent toughness resists deformation where softer, or less hard steels might succumb to chipping or rolling.
 
I must apologize I didn't make the point I wanted to very well. No.....the 1.2442 will do WONDERS for whatever you want it to do. Toughness is great, wear resistance is great, no stain resistance of course. I'm just saying that if I was after toughness, 1.2442 wouldn't be the one. Yes, it is tough steel for the carbide content it has, but you said "knives that can take a pounding". With the cost of importing that steel on top of where it really shines (thin hard edges.....and these thin hard edges are had because of it's level of toughness at those hardness levels), I would easily choose a different cheaper steel. 80CrV2, 5160, 52100 the like. Just going by the online prices of 1.2519 plus shipping, and what that steel is best suited for, I would use that exclusively for fine cutting instruments...not so much beaters. I'm just being a little over picky against using 1.2442/1.2519 in knives that will see a pounding. When I think of the capability of those steels, 1.2519 as well, and how hard they can be taken with a very fine edge, IMHO those steels are best left to slicer dicers! But hey....it's YOUR shop, my friend! Don't mind me....I'm just ranting!
 
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