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Dan Miller
 
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In answer to Ed's question I generally make tools. I get a lot of flack
from my wife and friends about using tools to make tools to make tools.
(right now I'm making a ball turning tool to make handles for tools)
Anyway, they see it as circular...I see it as fun.

Anyway, I want them to look nice as well as be functional and being a
relative novice at the lathe (I don't have a milling machine) I spend a
lot of time trying to find the right grind for the bits, the right speed
etc to get a nce finish. I used to buy all my steel from this steel
salvage yard near where I live but then realized that I know little
about the alloys I'm picking up. the Shape and size selection is great
though. I stumbled across a few pieces that machined really nicely and
that got me interested. Now I buy the stuff from a local online place
and that way I get the exact size, length, and alloy I want....something
to be said for that.As far as steel goes they sell 12L14, 1018, and 4130.

Lots of the stuff I make is threaded, and sometimes I make the nuts etc.
I've had little experience with the 12L14, sounds like strength-wise it
is fine. I worry about wrenches and stuff chewing it up if I make nuts
with it but perhaps this is unfounded as well. Is it noticeably less
stiff than 1018? Maybe I'll just stick with it. Is there ever a case
where 1018 is preferable?

I'll check out JM Tull as well Charles, thanks for your opinion.


Dan

tim wrote:

Charles A. Sherwood wrote:


What are the machining properties of 4130? Perhaps this is the best
compromise between finish and toughness?


4130 is a crome moly steel. Tough to turn; especially when compared
to leaded steel. Not exactly cheap to buy either.

I picked up a large bar of steel that appeared to be hot rolled.
It machined easily after removing the crusty surface. Sometimes
cold rolled (1018) machines well and sometimes it is tought to
get a good finish.

chuck



I buy my steel from JM TULL its a large steel company here in the US
and this is the discription of 12l14 in there catalog."Tull-led
12L14 provides superior machining properties,high cutting speeds, and
incresed tool life .Surface finish is uniformly smooth and bright .
parts close size accuracy the addition of lead has no efect on the
mechanicl properities or the internal soundness of the steel."
Here are the mechanical properties the catalog gives for
cold finished rounds.

1018 tensile psi 64,000 yield 54,000 elongation in 2 inches 15%
12L14 tensile psi 78,000 yield 60,000 elongation in 2 inches 10%
1144 tensile psi 108,000 yield 90,000 elongation in 2 inches 10%
4140 annealed tensile psi 102,000 yield 90,000 elongation in 2
inches18%
4140ht (heat treated rockwell 28 to 32)tensile psi 125,000 yield
105,000 elongation in 2 inches 16%

The 12l14 is not as tough as 1018 but has a higher tensile and yield
properities.Agian before anyone flames me these figures came from the
manufactures catalog.
Here is my thinking 1018 is junk metal its hard to cut and get a good
finish I try to avoid using it unless I have to weld it .
Most other alloys don't weld very well.