Lines in finish

Matt Rochester

Matt Rochester

Joined
Nov 28, 2014
Messages
1,864
If you look next to the reflection of the light then you can see these little lines in the finish. They look like a bunch of x's. This is 220 grit. I'm going to take these to a mirror finish. Problem is these lines never go away. I had this problem before and never figured it out. This steel, and the previous steel, came from Texas knife. Any suggestions would be appreciated. If you can't see what I'm talking about I will try to get some better pics. I am beginning to think it's something in the steel. I do my own heat treat. Could it be the grain?
 
Could it be something in the grain or something in the makeup of the metal? How many different mills make 440c or does most of it come from the same place?
 
It is usually an artifact of the earlier coarse grits. Go back a few grits and carefully re-sand. Don't go up to the next grit until all previous marks are gone.
 
Im not sure we are looking at the same thing. The marks im talking about are not scratches. At first I thought they were from the seem of the belts but some are squiggly. They are not very obvious and have to be in the right light to see them. I haven't seen it in any other steels and I finish them all the same.
Stacy E. Apelt - Bladesmith said:
It is usually an artifact of the earlier coarse grits. Go back a few grits and carefully re-sand. Don't go up to the next grit until all previous marks are gone.
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I don't mind sending this blade to someone if they think they could get a better idea whats causing it. This has shown up in all 6 knives I have made out of this steel. 4 were oyster knives and it wasn't as pronounced. I need to correct it if its something in my heat treat. If its in the steel then I need to make the supplier aware. I wont sell any of them in this condition.
 
What steel is it?

Never mind - just saw you mentioned it in the other post.
 
I'm assuming this is a blank cut from a piece of stock? We used to get lines like that in sheet metal, is from the mill rollers. Probably near end of life for them so they clamp a little tighter to eak out a little more life and make the next shift change them
 
Yugami said:
I'm assuming this is a blank cut from a piece of stock? We used to get lines like that in sheet metal, is from the mill rollers. Probably near end of life for them so they clamp a little tighter to eak out a little more life and make the next shift change them
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It is from a piece of stock. Is it usually all the way through?
 
Unfortunately my experience is with extremely thin sheet metal at a stamping shop, I just got into knives and working with larger steels. My gut says it shouldn't be because it was the finishing roller that did it, however my guts been way off before.
 
Took it down some with a 60 grit and then went back to 220. I put it some FC to see if it would show up better and it did. I'm lost. I guess I will chalk it up to bad steel. I am going to call Texas knife and see what they say.
 
Don Hanson III said:
Looks like grain pattern in the steel. What is the problem?
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I like figure in my woods but not in my steel! The problem is it's visible. When I take it to a mirror finish you can see it. This is only 220. The higher I sand the more it shows.
 
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All steel has grain to it-I don't generally work in stainless-but every stainless knife I own has visible grain structure in the right light. That particular pattern is odd-but Stacy's right. Run your heat cycling again and see if it goes away.
 
Looks like the dreaded "orange peel" effect to me. I'll bet you lunch it doesn't go away no matter how many times you bake it or how much you grind it - it's in the steel. As you already noticed, it will only be MORE noticeable the finer you polish it.

This is one of the reasons I simply won't use 440C or 154CM anymore. The steel coming out under those "grades" just isn't as clean and consistent as it once was. If you like those properties, but want a cleaner finish (and likely a tougher blade to boot), just use CPM-154 or CPM-S35VN. The small extra cost per blade is well worth it.
 
I have used Cpm154 and not had any problems but it is a bear to polish. I normally do a hand rubbed finish and use 440c for polished finishes
james terrio said:
Looks like the dreaded "orange peel" effect to me. I'll bet you lunch it doesn't go away no matter how many times you bake it or how much you grind it - it's in the steel. As you already noticed, it will only be MORE noticeable the finer you polish it.

This is one of the reasons I simply won't use 440C or 154CM anymore. The steel coming out under those "grades" just isn't as clean and consistent as it once was. If you like those properties, but want a cleaner finish (and likely a tougher blade to boot), just use CPM-154 or CPM-S35VN. The small extra cost per blade is well worth it.
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