A 1075 vs. 01 milling Question - Probably for Dan Gray and Mete

R

rlinger

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Why is it that milling, using same type end mill (HSS) and mill, 01 is so much easier on the end mill than 1075 is? I can mill O1 at least twice the rate as I can 1075 and even at that the end mill has about twice the life as when I mill 1075. To get any life out of the end mill I must run at about half the speed (rotaion and advance) as I can milling O1 steel. Not knowing better I wonder, is there something in O1 chemistry that makes it closer to free milling?

As a matter of fact, the pass is about 10 thousandths deep and a bit more than 1/4 inch in travel and about 15 passes per completed cut for about 150 mil total depth per final cut and actually I can cut about 12 to 14 mil deep per pass on O1 but NOT 1075. There are no fluids involved for either cooling or cutting. and yes, it is the WSK saw teeth I am cutting.

In reading my own post I am reminded by an Uncle of mine who once told me simply asking a question can give the answer. Perhaps I should Rockwell the difference between the two annealed steels. Not remembering well enough to be sure, I think I did do that many months ago with no effective difference.

Thanks.

RL
 
It's most likely the microstructure . I assume that the 1075 is a pearlitic and at that high a carbon content is difficult to machine .The O-1 is almost surely spheroidized annealed.
 
I knew you or Dan or both would come through, and yes - the O1 is as you say. Not looking for a solution but just a matter of knowing why. I'll stay with 1075 as the default for this particular knife anyway. Thanks Mete. I anxiously await Dan's experience since I know he to have been a tool and die maker.

Thanks and 73/DX.

RL
 
oh man.is that HAm Radio talk :) ;)


The 0-1 I get come butter soft RL - Try annealing the 1075 in the oven and see what happens.
 
Roger
yeahup I think you got..
I'd ck the Rockwell like said above.
I can't comment a lot on it because I don't use 1075
the only thing I could say,, if they are both the same Rockwell
O1 may be a bit more machineable because of it's extra goodies with-in.
more self lubricating maybe?:D

but really I'd look at the rock well, the 1095 I get is soft as putty..I can't see the 1075 being much differant.
 
Robert
O1 lists from .85 to 1.0 in carbon on my chart
so I'd think carbon wouldn't be the factor in this problem ? but it's just my thinking..:confused:
 
I think it's like Mete said, the O1 is annealed (since it can air harden if normalized, depending on thickness) while the 1075 is probably just normalized since air hardening isn't an issue.
 
Both are probably annealed, the difference is the structure, like Mete said.
O1 is generally spheroid annealed, while the other steel is just annealed. There is a special process used to spheroid anneal and it leaves you with a microstructure that is much easier to work with. O1 is marketed as a tool steel, and its pretty much a given that it will be machined. So that is the way it is commonly sold. 1075, is not a tool steel and would not be spheroid annealed unless you ordered it that way because it costs more to do.
If you wanted to, you could probably spheroid anneal the 1075 in your heat treat oven. You would have to look up the specs on it, because IIRC its about as detailed as heat treating can be.
 
I'm sure Robert is on the nose with this, my question was about the carbon content comment? only
Matt Shade said:
Both are probably annealed, the difference is the structure, like Mete said.
O1 is generally spheroid annealed, while the other steel is just annealed. There is a special process used to spheroid anneal and it leaves you with a microstructure that is much easier to work with. O1 is marketed as a tool steel, and its pretty much a given that it will be machined. So that is the way it is commonly sold. 1075, is not a tool steel and would not be spheroid annealed unless you ordered it that way because it costs more to do.
.
Click to expand...

so then Matt I'm wondering,:confused: , would 1095 be treated any different than 1075?
I ask this because
the last two batches of 1095 I got was so much softer than the O1 I use..

this happening to the unknowing would think :confused: OK what's happening here? yes we can get steels that are the same but not = H/T wise from the Factory.

I do want to mention for the guys that don't know , where the mention of air hardening on O1 was made,, O1 is an Oil quench steel. , though it will air harden to a point..I say this because the thread is for all to see.
 
Look at some microstructures. At .80 carbon you will have all pearlite for a normalized structure , it even LOOKS hard to machine ! Then compare a photo of speroidized annealed - a very different thing.
 
I think the best way to spheroidize [finer] would be to quench and temper at 1200F [subcritical anneal].
 
I'll go ahead and mill the ones I have yet to do as they are. Later I'll try some experiementing on some drop pieces.

Mete, I am CW only. Okay with you? 80 is fine. Let me know when and what frequency - NO lower than 35025 KHz. (KD8BZY)

DX

RL
 
This has been discussed a few times in various forms. The usual conclusion (and my own conclusion) is that most 10-xx barstock comes from the factory in mill form. The bars are not routinely annealed. Perhaps not even normalised. I've had bars where I've tested with a file and had it skate on some sections. In other threads about this issue, makers have found that their expensive cobalt HSS drill bits were being eaten up excessively fast.

I forge my 10-xx barstock stock, so its less of an issue, but I also keep a stash of 1095 steel that will be for a range of stock-removal projects. I send these to a professional HT-er to be annealed. The results after the pro annealing confirm my suspicions.

Jason.
 
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