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41L40 Steel (leaded)... Does It Rust Easily Like 12L14 does?

morsetaper2

Diamond
Joined
Jul 2, 2002
Location
Gaithersburg, MD USA
All,

I like to turn & machine 12L14 steel when it fits the need. But about it's biggest drawback is it's tendency to rust easily. Unless it's painted, powder-coated, plated, kept oiled, or some other sort of corrosion protection is applied.

Does 41L40 (leaded) steel have the same tendency to rust as readily as 12L14?

-MT2
 
Your 41xx series steels has just enough Chrome in it to slow down rust. I don't recall seeing a difference in the two in years past. We had both stored in the shop yard back at the family homestead and don't recall noticing a difference.
 
Hahahahah. The original inquiry referred to 12L14, which is notoriously fast and easy to rust. It is indeed easy to tell that from 1018 or similar steel alloy.

morsetaper2, I don't cut enough 41L40 to give you an answer with any confidence.
Carbon steel rusts once bare metal is exposed. Both of the alloys listed here will rust - we have bars of both materials in our shop and all of them have some level of oxidation on the surfaces. I will admit we did not conduct experiments on rate of decomposition between the two but as they say, "rust never sleeps".

We have some 41L40 lock rings that just came back from heat treatment but were not oiled by the supplier. There is active rust all over the pieces. On a cosmetic surface, any amount is too much.
 
All,

I like to turn & machine 12L14 steel when it fits the need. But about it's biggest drawback is it's tendency to rust easily. Unless it's painted, powder-coated, plated, kept oiled, or some other sort of corrosion protection is applied.

Does 41L40 (leaded) steel have the same tendency to rust as readily as 12L14?

-MT2
12L14 will rust what seems like immediately after cutting.
41L40 rusts fast, but not as fast as 12L14.
You'd have to cut the 2 pcs side by side to get a comparison.
 
I had the same problem and switched to 1144 stressproof that machines really nicely on my ancient bench lathe. The leaded steel would start rusting almost immediately after turning, so I stopped using it.
 
The lead in the 'L' free machining carbon steels promotes quick rusting. it forms a pretty bad electrolytic couple that doesn't protect the iron... Chromium will slow this down because of the oxide layer that forms on the surface. (I think, I'm not a metallurgist, nor do I play one on the television).
 
All,

I like to turn & machine 12L14 steel when it fits the need. But about it's biggest drawback is it's tendency to rust easily. Unless it's painted, powder-coated, plated, kept oiled, or some other sort of corrosion protection is applied.

Does 41L40 (leaded) steel have the same tendency to rust as readily as 12L14?

-MT2
That is a drastic difference in material choice. What are you making?
 
That is a drastic difference in material choice. What are you making?
I'm actually not using either for anything at the moment. I was just wondering about the tendency to rust characteristics of 41L40 compared to 12L14. I know you look sideways at 12L14 and it will begin to rust. Have no experience w/ 41L40.
 
I had the same problem and switched to 1144 stressproof that machines really nicely on my ancient bench lathe. The leaded steel would start rusting almost immediately after turning, so I stopped using it.
Actually I bought some 1144 for a current project. Looking at a list of uses and properties of various steels, I saw the two leaded steels. And that got me asking about the rust topic.
 
41xx material that is Q & T really machines very nicely. I prefer machining it over annealed any day. I don't run it slow either. Turning it, usually run it in the 240-340 SFM and I feed it as much as the machine will handle. Ken
 
I used 12L14 early on when I was learning how to turn, but noticed right away that it rusted quickly. Much prefer 1144 or 4140 now.

20 yrs ago at an auction I bought an ancient Hardinge Cascade hand turret lathe, and it came with hundreds of pounds of 9/16" round stock, 7"-9" long. The stuff cuts like a dream, and most of it was unrusted, even tho the shop was in the basement of a big, old lawnmower repair shop. Guy had some giant Warner Swazeys, etc, clearly knew what he was doing. So, what would screw machine shops have used for easy cutting beside leaded alloys? Sulfur?
 
I used 12L14 early on when I was learning how to turn, but noticed right away that it rusted quickly. Much prefer 1144 or 4140 now.

20 yrs ago at an auction I bought an ancient Hardinge Cascade hand turret lathe, and it came with hundreds of pounds of 9/16" round stock, 7"-9" long. The stuff cuts like a dream, and most of it was unrusted, even tho the shop was in the basement of a big, old lawnmower repair shop. Guy had some giant Warner Swazeys, etc, clearly knew what he was doing. So, what would screw machine shops have used for easy cutting beside leaded alloys? Sulfur?
Screw machine stock is 1212 or 100% machinability rating. My old Jorgensen Stock List show 1213 @ 136% or 1212. It emphasizes the material is resulphurized to achieve very fast machineing. The main sacrifice with screw stock is poor weld ability. 1144 stressproof is sort of a high end screw stock also not recommended for welding, however there are many heavy equipment pins in the world made of 1144 with an anti rotation strap welded on. All of these materials we’re around in the 1960s.
Actually I bought some 1144 for a current project. Looking at a list of uses and properties of various steels, I saw the two leaded steels. And that got me asking about the rust topic.
 
Good luck finding any 1212.
I've ran "screw machines" for 30 years and never once ran any.
I understand that it's the ref point, but I bet you'd have a hard time finding anyone that has ran any anymore.

And Stressproof and it's counterparts (1144) were developed in the 30's.
Not sure the timeline of the 1200 series, but likely before the 60's.


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I am Ox and I approve this post!
 
Good luck finding any 1212.
I've ran "screw machines" for 30 years and never once ran any.
I understand that it's the ref point, but I bet you'd have a hard time finding anyone that has ran any anymore.

And Stressproof and it's counterparts (1144) were developed in the 30's.
Not sure the timeline of the 1200 series, but likely before the 60's.


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I am Ox and I approve this post!
It might be my imagination, but it seems to me that 1144 is not the same as La Salle's product.

It just doesn't seem as hard, nor does it turn the same.

I'd picked up some "genuine" Fatigue Proof from Alro years ago for a pin on a tractor. Then recently bought some 1144 for another pivot pin on the same machine. I swear the 2 materials are different.
 
All Stressproof should be 1144 alloy (or pretty close), but not all 1144 alloy will be Stressproof. Not just a quibble over trademarks. There's quite a bit of processing that goes into Stressproof/Fatigue-Proof beyond just rolling out a round bar of the material. If you buy a bar of 1144, you generally don't know what's been done to it. And if it's substantially cheaper than the trademarked material, it probably didn't get most of that processing.

From the Pacific Machinery and Tool Steel Company website:
STRESSPROOF® is made by a patented process which consists of drawing the bar through a special die under heavy draft, then stress relieving it. This severe cold working combined with the stress relieving results in a high strength bar with good stability and exceptional machinability. STRESSPROOF® can often replace heat treated alloy steel for machined parts requiring hardness in the range 23-30 HRC. It can be induction hardened but should be watched for quench cracks because of the high sulfur and manganese content. Welding is not recommended. STRESSPROOF® exceeds ASTM A311, Class B.
FATIGUE-PROOF® is an even higher strength grade made by various combinations of mechanical working and thermal treatments. This high strength bar can eliminate heat treating in the 32-36 HRC range plus the secondary operations associated with heat treating, i.e., cleaning, straightening, re-machining and inspection. All this, in combination with free machining, works to reduce end costs. FATIGUE-PROOF® can be induction hardened using the same precautions as with STRESSPROOF®. Welding is not recommended.
 
It might be my imagination, but it seems to me that 1144 is not the same as La Salle's product.

It just doesn't seem as hard, nor does it turn the same.

I'd picked up some "genuine" Fatigue Proof from Alro years ago for a pin on a tractor. Then recently bought some 1144 for another pivot pin on the same machine. I swear the 2 materials are different.
1144 fatigue proof was some really nice material to turn. One of my favorites.
 








 
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