Deeply pitted 440c

J

jasperdog032469

Joined
Mar 14, 2007
Messages
115
I'm getting ready to order dome more steel. I'm thinking of trying Admiral this time. What I'm wondering is if the steel I get from them will be pitted or if it is smooth. Not looking for perfect or anything, but by the time I get what I'm using smooth I've had to use two or three belts and the thickness is much less than what I've started with.

Thanks
 
Seeing that their 440C is hot-rolled, my guess is that there will be the same mill scale that you've experienced before. Most of my occasional steel orders come from Tracy at USAKnifemaker.com now days. The stuff he gets from his supplier is "descaled". I believe they pickle it to remove the scale. I get the CPM154, and it still has an occasional light pit, but not anything like some of the 440C and ATS34 I've used in the past. BTW, 154CM is basically ATS34, and the CPM154 is a particulate form of the same steel with better alloying distribution, slightly higher hardness, and slightly more toughness.

http://www.usaknifemaker.com/store/metals-stainless-cpm-d2-steel-c-93_35.html

If you specifically want 440C, try to find it precision ground, or you can pickle it yourself by soaking several hours (usually overnight) in a vinegar bath.

--nathan
 
Also 440C and ATS34 is Japanese origin, which is notorious for inclusions...that's why I stick with CPM154...its red, white and blue.
 
This is an honest question. I wonder if the term "scale" is being misused here? For instance, 440C from crucible comes "descaled" which really just means sandblasted. It is still somewhat "pitted" (rough surface) from the blasting.

I was of the opinion that the above would be referred to as "mill finish" and scaling would refer to something right out of rolling - or also to something damaged during heat treat or part of the normal process of forging?

I don't think I've seen much out of Admiral or Crucible that I would have descibed as having scale. Opinions?

:confused:
 
I think your definitions are correct. In my mind "mill scale" is the hard bark found on a number of steels that have been hot rolled but not finished. It's a dark grey, very hard, and it takes a toll on belts to remove and blades while cutting. Some 440C I've ordered in the past has been heavily endowed with this along with some quite deep pits.

I guess it's sand-blasting that crucible's finishers use to descale and not pickling, but whatever they use, it greatly reduces the amount of work I have to do. Either way, there is some prep work to be done to remove pits.

--nathan
 
You must log in or register to reply here.
Back
Top