440c versus ats 34

I've seen it on a good bit of 440C and seen it quite often on D2 when taking it to a mirror finish.

The cleanest 440C and ATS 34 I've worked with was from R. W. Wilson but he doesn't have any more of the 440C. At least not in the sizes I use.

RW and I discussed this once and he told me that steel was Hitachi and was rolled in bar stock. He told me one time you will see more of that cloudiness in the plate steels but don't know if that has to do with the way it is rolled or just the mill it came from. The steel we were getting from Hitachi was in bars where as most other suppliers I've gotten it from you can tell it's been sheared from a wider plate.

RW was checking on another mill run of that from Hitachi but the price they gave him was as much or more than the CPM and CTS steels so I'm leaning in that direction for the future.

Hopefully Carpenter is doing as good of job on the CTS batches they are making for Scott Devanna as the samples they have sent me. If so the CTS-40CP is the way to go if you want some clean 440C. It is 440C powdered steel.

I can't decide if I like it or the XHP better.

I don't think you will see this in the powdered steels because of how it's made.
 
Just to add the Carpenter 40CP is 440C but it probably has a higher carbon content than some of the suppliers. If I remember correctly it is 1.14. If you look at the make up of steels the carbon content for 440C has a very wide range for some reason. I believe this may be why 440C from some suppliers makes a much better blade than others. The Hitachi 440C RW Wilson was getting will hang in there with ATS 34 or 154CM all day long but has more corrosion resistance. That steel was a dream to work with but I never realized how much until the supply dried up. I also have some plain 440C from Carpenter also but I haven't had a chance to make any test blades from it.
 
About 20 years ago I was selling a lot of hunting knives. I was using 440-C . Along came ATS-34 .I decided to try some and do some serious testing. I found that ATS-34 had better edge holding by say 20% when both steels were heat treated in their proper recommended meathods in a vacuum chamber and with the real nitrogen treatment. 440-C always did take a better finish but I never say or heard of any signs of corrosion with the ATS-34. I did receive a bunch of ATS-34 that was full of impurities and really showed it when finished.
Now I don't often use a stainless steel. I use Damasus for almost all my work. I recently went back to stainless and tried the CPM154, 154CM,and S30V. The CPM154 and 154CM are great to work with and do finish up lovely with with a polish or satin finish. I will not work S30V again. Frank
 
Thank you kindly for the info, gentlemen. I was beginning to think I was losing my mind (what's left of it) or seeing things, lol. Just to be sure, I showed the blades in question to my lady and she can see it too.

I've read a lot of stories similar to Frank's about ATS-34 with impurities, I suspect that's similar to what happened with this bar of 440C I have. I've decided to go ahead and have the blades HT'ed and test them, if they keep a good edge I'll finish them up with a basic satin finish. Probably let them go at a discount but at least I might make up my costs. If I have ANY doubts about them being good user blades they will go in the "oops" bucket. Nothing leaves my shop unless I would carry it confidence.

In future I'll be more careful about who I buy my steel from.
 
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James, the bad ATS that Frank mentioned happened to lots of people. It seems that Hitachi Metals ran some bad stuff. I quit using it a long time ago because the US government slapped an import duty on it because there was a US equivalent - 154cm. Because of that duty it sold for the same price as 154cm, so I bought domestic steel.

You are describing the defects as "floaters" like most of us "see" as threads just off the center of our vision in bright sunlight. I've seen this as sort of a grainy look on other stainless steels and D2. It seems to disappear with a good hand finish. It's not nearly as grainy as what you see in Crucible's "V" steels. What I was describing is more of a large splotching effect. On a couple of ATS folder blades it sort of resembled a radical hamon. Yeah, it was that big! On the one 440c blade years ago it was this huge splotch like I dropped some chunk of gooy stuff on it.

THe only problems I've had with CPM154 were some tiny voids in the earliest batch. It seems to be very clean stuff now. I've also used some of the Bohler/Udeholm steels with no problems. I particularly like Elmax. Harder to finish than 154 and 440 but not as hard as Crucible's "V" steels, and the finish is more like CPM154 when you're done.

As for loosing your mind and seeing things, well, we are a bunch of guys who make knives. . .

David
 
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