PDA

View Full Version : can you tell if a knife is with white steel or blue steel by just looking?



orange
12-28-2011, 11:16 PM
It may sound a silly question but how can you tell a knife is made with white steel or blue steel by simply looking (some knife has Kanji showing what steel the knife is made of but what I am talking about is for the knives that do not have such Kanji.)
I have a few blue steel knives and a few white steel knives. To me, light reflection (under the same light source) from the blue steel knives looks different from that from the white steel knives. I don't know if this is just me imagining something unreal or what.
So, I wondered what you guys' experiences are.

Eamon Burke
12-29-2011, 12:06 AM
my theories:
1. Observer bias
2. Different patinas

Eamon Burke
12-29-2011, 12:07 AM
3. You sharpen them the same, but they are different steels and different hardness, so they take a different level of polish from identical abrasives, and light acts differently.

ajhuff
12-29-2011, 12:22 AM
+3

-AJ

JBroida
12-29-2011, 12:51 AM
nope... only by kanji :)

Peco
12-29-2011, 06:26 AM
So is that a yes or no :D Just kidding :razz:

Schtoo
12-29-2011, 08:29 AM
Theoretically, it's not out of the realm of possibility.

Practically, spark test is the only way to be sure without any stamped in or pre-divulged information. White steel throws lotsa sparks, blue steel throws few/none when touched against a grinder.

Or sharpen the dang thing.

(But taking things to the grinder is more impressive and has significant pucker factor applications. :) )

Stu.

orange
12-29-2011, 10:11 AM
Alright, what I would add is even the color of patina looked to be slightly different when the same food was cut. :O
Looks like it all were in my imagination...amusing!

karloevaristo
12-29-2011, 11:09 AM
great question! been thinking about this also...

if i may I have a follow-up question: can anyone even tell if they're sharpening a white or blue steel just by feel? what are the differences/similarities when sharpening the two?

chefofthefuture
12-29-2011, 02:00 PM
I would say you can tell based on the patina, however the color of the patina has more to do with what your cutting than the steel. I'd assume though if you literally cut the same food, handled the knives exactly the same, removed all variables... then the two steels would patina differently due to their different compositions.

C_Dawg
12-29-2011, 02:08 PM
in my experience, white steel is a bit more sensitive to discoloration when cutting foods.

Seb
12-29-2011, 02:29 PM
Could be my imagination but I always fancied my white steel took a grayish patina and the blue steel a slightly bluish patina.

Eamon Burke
12-29-2011, 02:48 PM
Seb, if you knew which steel was which, you'd probably use them for cutting different things, no?

99Limited
12-29-2011, 02:53 PM
Hey, maybe someone with both steels could tell the difference by giving each one a good couple of licks to see if they taste different. :razz:

Delbert Ealy
12-29-2011, 03:01 PM
Hey, maybe someone with both steels could tell the difference by giving each one a good couple of licks to see if they taste different. :razz:

The wolfram makes the steel taste spicy!!! :viking:

Del

wsfarrell
12-29-2011, 03:02 PM
A commercial knife sharpener I know who has sharpened > 100,000 knives (most of them on a custom setup with 4 bench grinders) carries a magnet in his pocket to help assess steel. If the sparks aren't conclusive, he can usually settle it with the magnet.

orange
12-29-2011, 07:41 PM
Could be my imagination but I always fancied my white steel took a grayish patina and the blue steel a slightly bluish patina.

Yeah!! I am not the only one!!

ajhuff
12-29-2011, 10:42 PM
A commercial knife sharpener I know who has sharpened > 100,000 knives (most of them on a custom setup with 4 bench grinders) carries a magnet in his pocket to help assess steel. If the sparks aren't conclusive, he can usually settle it with the magnet.

I don't get how the magnet trick works. Only thing I can come up with is, is it like a really really weak magnet that is has greater attraction to lower alloy, higher iron contents?

-AJ

DevinT
12-29-2011, 10:57 PM
It would be difficult at best to tell the steel by looking at it. However, sometimes I can see the dendrites in the steel as I am polishing it, which would tell me that the steel has large carbides, which may be detectible in the blue steel.

All steels have subtle color differences, which can be seen in pattern welded steel before it is etched. So yea, I guess it is possible.

As far as the magnet trick, I don't know except that you could tell if the steel had a good amount of retained austenite. Austenite is non magnetic. The higher alloy steels would have more RA than simple steels for the most part. The magnet would not have the same force of pull.

Hoss

Eamon Burke
12-29-2011, 11:05 PM
Well, we got a "sometimes" from Mr. Thomas, which means a "No way" for me. :lol2: