01 or D2 silly me

johnnym

johnnym

Joined
Dec 13, 2005
Messages
170
About three months ago i ground out 4 blanks from 1/8 stock, but i did not mark them. Now i dont know if they are 01 or D2 steel. Is there an easy way to tell? I Just dipped them in water along with some known D2 figuring if they rust about the same by tomorrow, they are probably d2, not very scientific :(

Any suggestions would be appreciated.

-John
 
what i would do is mesure the knifes volume by putting it in a graduated countainer filled with water and see how much water the knife displaces. then weigh the blade and see how much it weights. D2 is 7.68 grams per cm3 (CC of water) and O1 is 7.83 grams per cm3.
then devide knive weight in grams by knife volume in cm3 (CC of water) and see what number you get.
 
.05 grams difference is going to be hard to accurately measure, especially eyeballying the water displacement and counting for scale accuracy.

If you have a known piece of D2 then I might try a spark test to go along with the rust test. Where I live, leaving it outside overnight will develop a nice fresh orange rust on O1 provided it's clean. If you have an oven, heat treating a blank like D2 would be a simple way to find out if it's not O1.

I wanted to add that the weighing method doesn't have any way to account for voids, inclusions or alloy variance.

JTKnives said:
what i would do is mesure the knifes volume by putting it in a graduated countainer filled with water and see how much water the knife displaces. then weigh the blade and see how much it weights. D2 is 7.68 grams per cm3 (CC of water) and O1 is 7.83 grams per cm3.
then devide knive weight in grams by knife volume in cm3 (CC of water) and see what number you get.
Click to expand...
 
O1 will harden at 1500. D2 - not so good.

I'm guessing a ferric chloride etch (or even vinegar) would have less effect on D2 than O1 - but that would still require a known scrap

Rob!
 
Yep, D2 is nearly stainless. Rub a piece of lemon against the samples and see which one develops the patina.

Old timers used spark test a lot. See if you can score a piece of known material and spark-test-compare it to the unknown steels. You will see distinctly different sparks thrown.

O1 is likely to be more magnetic as well (???)

And lastly, score 2-3 cans of spray paint in different colors and get into habit of marking all of your steels. Spray entire bars, this way even cut-offs can be easily IDd.

Mark the cans themselves with the type of steel you use em for.

I can not give proper credit to the author of this idea ... some metalworking site on the Web
 
Grab a known sample of each the d2 and o1 and spark test the sample against a grinding wheel and spark the blade . Match the spark plume. and bob's your uncle. Paul
 
Like Rashid said, The best way is to mark it before you forget which is which. I had to throw/give away about 50 blades because I could not remember what they were. I always mark my stock every 6 inches on both sides. Now I can figure out what it is without trying to spark it.
 
Thanks for the help. Based on both the rust test and the spark test i am convinced they are D2. I will also take your advice and color code present and future blades with spray paint.

JT your suggested method was very creative and scientific, however i dont feel that i have instrumentation precise enough to perform it with any degree of confindence.


-John
 
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