pits in D2

As a beginner knifemaker I've have found that small pits appear in D2 when I work it down to 400-600 grit after it has been heat treated. I talked to Rob Simonich who does the heat treating and he also has seen it and thinks it maybe the qaulity of the steel. How about you guys, ant thoughts or suggetion on this problem.

Kim
 
Dr.Lathe

Dr.Lathe

Joined
Aug 4, 1999
Messages
2,596
The pits!
I use D2 for all my small working knives. I have encountered the pits on ocaision. I don't think that the problem is in the heat treat. I have found them in D2 tooling that I have bought at work from very well know die companies!! I heat treat up to a dozen blades at a time and may only find that funny looking pitting on one blade. My thought is that is is something in the steel.
Neil

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http://members.aol.com/blademakr/BlackwoodWP.html
 
I've had those pits in all my blades both ATS-34 and 12C27, and in both steels they were rather deep.Is this just bad luck,or will it happen every time I have a blade hardened ?
 
I bet the pits you are talking about are on the flats of the blade at least 90% of the time.

In my polishing experience the pits that show up as the finishes get finer and finer are no more than pits that were not removed during the initial belt sanding. The coarse scratches from the lower grit belts hide the pits until the finish gets smoother.

The first rule of metal polishing is that there are no shortcuts especially at the beginning stages.

A tip alternate grind angles at each belt change, anything not removed at the previous stage shows up better and you can go back and remove it sooner. Do not run subsequent belts in the same direction or you will miss scratches and pits.

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george
www.tichbourneknives.com
sales@tichbourneknives.com

 
question...where do you get your steel and what grade is it.....i would imagine the pits are part of the bark that you arent getting off...try going a little deeper... they could be crap in the steel...used to see it a lot in 154cm.....the smog from the mill gets rolled into the steel...but in d2 i kinda doubt it....do you buy it from an industrial supply house or a knife steel distributor.....try getting some die perfect. no pits in that!!!!!!!or maybe buying it precision ground....

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http://www.mayoknives.com


 
Here is the pit analysis!!! I examined two pits tonight at work one on a die and one on a knife. I wouldn't call them a pit, it is more like a foreign particle that seems to have been rolled into the steel. Our QC inspector that was kind enough to let me use his microscope, said it was a metal BOOGER! I had to grind about .060 off the face of the die go get rid of it!! The material that the die punches is stainless and it sort of highlighted the imperfection. It apears to be as hard as the surounding material. I just thought I would share my findings with everyone.
My knife steel, I believe, came from Admiral but I am not sure. I am going to do some research before I buy anymore D2.
Who has the best price on the best D2???
Neil
 
i'm pretty sure sheffeild knifemaker's supply has it the cheapest. i haven't worked on d-2, but i was afraid of it pitting, i probably will now. and george remember the knife i said i was making a while back, i'm almost finished with it, i'll have to send you a picture.
 
personally...i wouldnt worry about it one bit..d2 is for working knives....a little pit here and there isnt going to matter one little bit....one thing i have against d2, and the main reason is stopped using it.. it rusts WAY too easy for a steel with 12% chromium....takes a great edge though..and keeps it for a while....nothing like 440v though....

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http://www.mayoknives.com


 
I've had quite a bit of D-@ with pits it dose no thinder the working of the blade. But i just prefer not to use it unless a cutomer asks for it. Iprefer the stainless or as more politically correct the stain resistant types of steels. Steels of the 440C and ATS-34 with Sub-ZeroQuench will cut I feel as well as Most tool steels if properly heat treated, and as I do all of my own heat treating and sub-zero quench I know what I have in my blades. But, that and a dollor will get you a dozen opinions or a couple of onions.
Good Cutting takes little work, the work is getting good cutting.


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Curtis Wilson -
Wilson's Custom Knives, Engraving, and Scrimshaw
 
Thanks for all the info! I would probably have to agree with George on this one. The pits where on the flats and I needed to work the steel a little more. I was able to sand them out so no harm done.

Kim
 
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