Grain Size - how did Nickolson do that!

[Sando]

OK I finally broke a 5160 blade and compared it to a Nickolson file and a piece of S30V as it comes from the factory.

The grain in my 5160 looked about like the S30V. However, the Nickolson file was AMAZING. It was a round file; the center core was coarse, but the bulk of it was creamy smooth!

Is that what my knife blades are supposed to look like?

Steve

 

[mete]

S30V as it comes from the factory is spheroidized annealed, it should have fairly large grains. The file is probably made from something like 1095,W1,W2 and is fairly shallow hardening therefore the center will be pearlite and the outside will be martensite.Certainly the S30V will have as fine a grain when hardened. Remember that grain size reflects on the steels toughness and fracture tests will give you a comparative grain size to compare different heat treating procedures. It's a quick simple test .

 

[Sando]

Thanks,

So should I keep testing/fixing until I can get a grain size like a file?

Steve

 

[mete]

Try to get the minimum grain size for one steel rather than comparing it to another.