Hi guys,

I've just set up a Victor 16 x 40 lathe and did some practice turning on a
2" hot-rolled mild steel round. No matter what variables I played with I
never got a satisfactory surface finish. The tooling seemed to pick-up or
drag metal, and this would lead to small gouges in the finish. I tried
various things, but never could eliminate it consistently.

Any thoughts?

Thanks,

Damian

Try a bit of solid lube or oil on it, and also honing the end of the
cutting tool helps to eliminate BUE (Built up Edge) which is whats
happening. Minor imperfections, can make stock build up on the cutting
tool edge which then scares or drags the turned surface. Are you
useing HSS or carbide? Carbide likes a higher speed and feed than HSS
does.

Some hot rolled steels are horrible to g et a decent finish on, so it
can take a bit of practice and experimenting with speeds. feeds, lube,
depth of cuts, and one other thing that helps is just grind a slight
radius on the cutting tools tip, and hone it, often makes the
difference.

On Mon, 13 Mar 2006 20:22:49 -0500, "Damian Huckle"
wrote:
Hi guys,

I've just set up a Victor 16 x 40 lathe and did some practice turning on a
2" hot-rolled mild steel round. No matter what variables I played with I
never got a satisfactory surface finish. The tooling seemed to pick-up or
drag metal, and this would lead to small gouges in the finish. I tried
various things, but never could eliminate it consistently.

Any thoughts?

Thanks,

Damian


--
\\\|///
( @ @ )
-----------oOOo(_)oOOo---------------


oooO
---------( )----Oooo----------------
\ ( ( )
\_) ) /
(_/
The original frugal ponder ! Koi-ahoi mates....

Damian Huckle wrote:

Hi guys,

I've just set up a Victor 16 x 40 lathe and did some practice turning on a
2" hot-rolled mild steel round. No matter what variables I played with I
never got a satisfactory surface finish. The tooling seemed to pick-up or
drag metal, and this would lead to small gouges in the finish. I tried
various things, but never could eliminate it consistently.

Any thoughts?

Thanks,

Damian

Got Carbide?

Coolant/Lubrcant?

Had a recent experience with one of he apprentices in our shop. He was
trying to get a decent finish on some hot rolled stock with HSS.
Couldn't.

A carbide insert and a heavy cut at high rpm left a mirror finish.

Pretty unnerving with all the hot chips rattling around, esp. for the
guy that was not all that comfortable in front of the lathe yet.

We ended up making the part od 12l14 and all went well.

Cheers
Trevor Jones

"Damian Huckle" wrote in message
news
Hi guys,

I've just set up a Victor 16 x 40 lathe and did some practice turning on a
2" hot-rolled mild steel round. No matter what variables I played with I
never got a satisfactory surface finish. The tooling seemed to pick-up or
drag metal, and this would lead to small gouges in the finish. I tried
various things, but never could eliminate it consistently.

Any thoughts?

Thanks,

Damian



As Roy said it can be hard to get a good finish on hot rolled steel. I've
found the same as you - try finding some "free-machining" steel it turns
well with a nice finish. I don't know exactly what "free-machining" means,
perhaps some one else will enlighten us. I guess the alloy composition gives
it nice machining properties.

rob

"Damian Huckle" wrote in message
news
Hi guys,

I've just set up a Victor 16 x 40 lathe and did some practice turning on a
2" hot-rolled mild steel round. No matter what variables I played with I
never got a satisfactory surface finish. The tooling seemed to pick-up or
drag metal, and this would lead to small gouges in the finish. I tried
various things, but never could eliminate it consistently.

Any thoughts?

Thanks,

Damian



Cold rolled (1018) causes the same problem I have had much better results
turning 4140. It seems to be a good general purpose steel that can also be
tempered a bit.

Jack

Wow, great response! I was fairly vague in my post, so I'll fill in a bit
of detail:

I tried a few types of tooling, mostly negative rake carbide-insert type of
various shapes, with no real difference in the finish between tools. I had
the best luck with a cheap-and-cheerful standard carbide tool (not an
insert) with a positive rake, but it was still hit and miss

I checked the height of the tool, and tried from dead center to slightly
above. Speed didn't seem to make much difference, although the finest feed
availiable on the lathe (0.003" / rev) seemed best. I tried both with flood
coolant, cutting oil, and dry.

Still the tool would seemingly pick-up a burr and drag a groove for about
one rev and release it. I'm concerned because the grooves would be a bit
deep for a good polish with emery, and the dimensional tolerances would be
out.

The toolpost and all other parts of the system seem very rigid. I put a
dial indicator right on the tool while it was cutting and didn't see more
that 1/10 thou movement in the tool (up and down).

The suggestions I've seen from your replies have included the following:
type of lube, grinding for a steeper front rake to prevent burring, higher
speeds with the carbide inserts, etc. Hot-rolled mild steel is probably the
most common stock for a lathe. Has anyone got a suggestion based on the
additional info above?

Thanks in advance, and for the earlier replies. Great suggestions - maybe
the additional info will help.

Damian

"Damian Huckle" wrote in message
news
Hi guys,

I've just set up a Victor 16 x 40 lathe and did some practice turning on a
2" hot-rolled mild steel round. No matter what variables I played with I
never got a satisfactory surface finish. The tooling seemed to pick-up or
drag metal, and this would lead to small gouges in the finish. I tried
various things, but never could eliminate it consistently.

Any thoughts?

Thanks,

Damian

Rob wrote:

"Damian Huckle" wrote in message
news
Hi guys,

I've just set up a Victor 16 x 40 lathe and did some practice turning on a
2" hot-rolled mild steel round. No matter what variables I played with I
never got a satisfactory surface finish. The tooling seemed to pick-up or
drag metal, and this would lead to small gouges in the finish. I tried
various things, but never could eliminate it consistently.

Any thoughts?

Thanks,

Damian




As Roy said it can be hard to get a good finish on hot rolled steel. I've
found the same as you - try finding some "free-machining" steel it turns
well with a nice finish. I don't know exactly what "free-machining" means,
perhaps some one else will enlighten us. I guess the alloy composition gives
it nice machining properties.

rob


Free machining steel has, pardon the word, "Lead" in it. 12L14, leaded
steel, cuts real easy with that addition of lead. Sulfur in the matal
will make the metal cut easier too. The smaller the tool nose radius
the easier it is to get a good finish. HSS bits will give you a decent
finish at lower speeds. Carbide needs to run at a surface speed of about
600 feet per minute to get a good finish. On a finish cut you should be
taking at least .010 or it will tear the metal. Also you may have
crappy metal with a lot of "junk" in it. Some day you may be lucky
enough to cut through an unmelted tap or piece of stainless wire rope.

John

According to Trevor Jones :
Damian Huckle wrote:

[ ... ]

I've just set up a Victor 16 x 40 lathe and did some practice turning on a
2" hot-rolled mild steel round. No matter what variables I played with I
never got a satisfactory surface finish. The tooling seemed to pick-up or

[ ... ]

Got Carbide?

Which may or may not improve things, depending on other factors.

Coolant/Lubrcant?

Which should to an excellent job of improving things, given a
good sharp tool, properly set.

[ ... ]

We ended up making the part od 12l14 and all went well.

Which is a lovely metal to work on, but which typed as you have
it is likely to confuse someone who is not accustomed to it. Try
"12L14", where the 'L' is upper case, so less likely to be confused with
another '1' (one).

And the 'L' here usually means that there is lead in the alloy,
which does significantly improve machinability. (Though on some alloys,
it can mean other things.)

Enjoy,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

I would probbaly go with positive rake inserts as its a lot eaier to g
et a better finish.......even though your lathe should be plenty
ridgid to use negative, I get a better finish with positives. Run the
brazed carbides at higher pseeds and feeds as well, and carbides do
not like to take whisker cuts, so pl;an your cut accordingly.

As for lube I Use automatic transmission fluid, and it works fantastic
and is about as cheap as you can get.....doe snot rust, works fine
with anything I mill or turn, and it does not staiun metal.

Any steel with a L in the alloy will be free machining or leaded
steel, 14L10 is one in particular. I think the lead in the steel acts
as a lube of sorts, but not entirely sure on that, but most leaded
steels IIRC can not be adequately heat treated, so thats a draw back..

I always run my cutting tools cutting edge dead on centerline.

Regards


On Tue, 14 Mar 2006 20:53:53 -0500, "Damian Huckle"
wrote:
Wow, great response! I was fairly vague in my post, so I'll fill in a bit
of detail:

I tried a few types of tooling, mostly negative rake carbide-insert type of
various shapes, with no real difference in the finish between tools. I had
the best luck with a cheap-and-cheerful standard carbide tool (not an
insert) with a positive rake, but it was still hit and miss

I checked the height of the tool, and tried from dead center to slightly
above. Speed didn't seem to make much difference, although the finest feed
availiable on the lathe (0.003" / rev) seemed best. I tried both with flood
coolant, cutting oil, and dry.

Still the tool would seemingly pick-up a burr and drag a groove for about
one rev and release it. I'm concerned because the grooves would be a bit
deep for a good polish with emery, and the dimensional tolerances would be
out.

The toolpost and all other parts of the system seem very rigid. I put a
dial indicator right on the tool while it was cutting and didn't see more
that 1/10 thou movement in the tool (up and down).

The suggestions I've seen from your replies have included the following:
type of lube, grinding for a steeper front rake to prevent burring, higher
speeds with the carbide inserts, etc. Hot-rolled mild steel is probably the
most common stock for a lathe. Has anyone got a suggestion based on the
additional info above?

Thanks in advance, and for the earlier replies. Great suggestions - maybe
the additional info will help.

Damian

"Damian Huckle" wrote in message
news Hi guys,

I've just set up a Victor 16 x 40 lathe and did some practice turning on a
2" hot-rolled mild steel round. No matter what variables I played with I
never got a satisfactory surface finish. The tooling seemed to pick-up or
drag metal, and this would lead to small gouges in the finish. I tried
various things, but never could eliminate it consistently.

Any thoughts?

Thanks,

Damian



--
\\\|///
( @ @ )
-----------oOOo(_)oOOo---------------


oooO
---------( )----Oooo----------------
\ ( ( )
\_) ) /
(_/
The original frugal ponder ! Koi-ahoi mates....

"DoN. Nichols" wrote:


We ended up making the part od 12l14 and all went well.

Which is a lovely metal to work on, but which typed as you have
it is likely to confuse someone who is not accustomed to it. Try
"12L14", where the 'L' is upper case, so less likely to be confused with
another '1' (one).

And the 'L' here usually means that there is lead in the alloy,
which does significantly improve machinability. (Though on some alloys,
it can mean other things.)

Enjoy,
DoN.

Indeed, DoN.

My Bad! Thanks for pointing that out. I understood what is written when
I read through it, but I knew what I was trying to say!

Cheers
Trevor Jones

Funny! I wondered where that tap went!

Thanks for the insight.

"john" wrote in message
...


Rob wrote:

"Damian Huckle" wrote in message
news
Hi guys,

I've just set up a Victor 16 x 40 lathe and did some practice turning on
a
2" hot-rolled mild steel round. No matter what variables I played with I
never got a satisfactory surface finish. The tooling seemed to pick-up
or
drag metal, and this would lead to small gouges in the finish. I tried
various things, but never could eliminate it consistently.

Any thoughts?

Thanks,

Damian




As Roy said it can be hard to get a good finish on hot rolled steel. I've
found the same as you - try finding some "free-machining" steel it turns
well with a nice finish. I don't know exactly what "free-machining"
means,
perhaps some one else will enlighten us. I guess the alloy composition
gives
it nice machining properties.

rob


Free machining steel has, pardon the word, "Lead" in it. 12L14, leaded
steel, cuts real easy with that addition of lead. Sulfur in the matal
will make the metal cut easier too. The smaller the tool nose radius the
easier it is to get a good finish. HSS bits will give you a decent finish
at lower speeds. Carbide needs to run at a surface speed of about 600 feet
per minute to get a good finish. On a finish cut you should be taking at
least .010 or it will tear the metal. Also you may have crappy metal
with a lot of "junk" in it. Some day you may be lucky enough to cut
through an unmelted tap or piece of stainless wire rope.

John

Roy wrote:
.....doe snot rust, ...

Is doe snot rust worse than buck snot rust? 8-} Bob

For some reason or other, I have spaced between the "e" and the "s"
and wound up with doe snot numerous times........I guess I am thinking
too fast for what I can type or just plain careless anymore when it
comes to typing and fixing errors......

On Fri, 17 Mar 2006 16:35:31 -0500, Bob Engelhardt
wrote:
Roy wrote:
.....doe snot rust, ...

Is doe snot rust worse than buck snot rust? 8-} Bob

--
\\\|///
( @ @ )
-----------oOOo(_)oOOo---------------


oooO
---------( )----Oooo----------------
\ ( ( )
\_) ) /
(_/
The original frugal ponder ! Koi-ahoi mates....