# Turning Hr Steel



## AGCB97 (Jun 18, 2016)

Is it possible to get a reasonable finish when turning hot rolled stock? I've just been using it to practice turning but the finish comes out terrible, like its torn off. What type and shape of tool would be best? As I say, it's just for practice cause I have it and it's cheap.
Thanks
Aaron


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## Wreck™Wreck (Jun 18, 2016)

Using inserted carbide tooling keep the SFM as high as possible for the diameter being turned and as high a depth of cut as the machine will handle whilst holding dimensions. Do not be shy on the feed rate either and if finish is a priority use flood coolant.

Can't help you if you are using HSS tooling as I haven't run a turning job with it in 30 years.

Last week I ran 300 parts from 1 3/8" 1018 hex stock, 1500 RPM's, .050 DOC and .010 IPR feed for roughing and .008 DOC at .005 feed for finishing and the finish was excellent using an 80 Deg. negative insert with a .015 nose radius designed for interrupted cuts from Sandvik.


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## 4GSR (Jun 18, 2016)

Wreck is 100% correct if you're making a paycheck or have the budget to invest into modern tooling and machinery. But us H-M must look at things a lot different.  
Take your piece of HSS and do some sharpening on it.  You want a nose radius of 1/32 to 1/16, depending on the size of your lathe.  Next, put a healthy back rake or top rake on the tool to give it a shear action when cutting. Last hone the edges until they are near razor sharp! Including the nose radius.  As Wreck said use the coarsest feed as you can for roughing on hot rolled mild steel (A-36, 1018-1026 grades and others).  Coat the surface of the part that you are turning with a good cutting oil.  This should remove the "dragging" or "build up" as you see on the surface currently.  Back off on your feed rate to around .005-.010" on your last two or three final passes. Keep applying cutting oil to the surface on the last cuts.


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## Andre (Jun 18, 2016)

I use a single cut pillar file to help deal with bad finishes sometimes. It's also very easy to sneak up on a diameter when filing.


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## kd4gij (Jun 18, 2016)

If it is from the big box stores, A file and emery is going to be your friend.


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## Wreck™Wreck (Jun 18, 2016)

I do not discourage home shop machinists, I try to encourage them with the little wisdom that I have gained over the years, anything that I post has worked for me.
Doing this for a living gives one a different perspective.


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## savarin (Jun 18, 2016)

I use a shearing bit with very slow auto feed to finish off my hot rolled steel.
It leaves a finish that only needs a tiny bit of emery cloth to polish.


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## FOMOGO (Jun 18, 2016)

Wreck™Wreck said:


> I do not discourage home shop machinists, I try to encourage them with the little wisdom that I have gained over the years, anything that I post has worked for me.
> Doing this for a living gives one a different perspective.



 Doing it for a living, definitely makes a difference in one's approach, and generally means stouter, and higher quality machines to do the work. On my 12" Craftsman I have also made good use of a file and emery cloth to get a good finish. I'm looking forward to eliminating some of those steps with the new to me TOS I've yet use.  The great thing about this forum, Is that you get so many different, and valid approaches to to the same issue. Mike


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## stupoty (Jun 19, 2016)

savarin said:


> I use a shearing bit with very slow auto feed to finish off my hot rolled steel.
> It leaves a finish that only needs a tiny bit of emery cloth to polish.



Their dead handy for steel that just seems to be very very gummy and for an amazing finish with very shalow doc.

I use hss tools almost exclusivly but i use feed's and doc along the lines of what wreek wreek sujests, (less rpm though my lathe dosn't go that fast  )  also I find a very slight nose radius works well for me, I generaly stick to my favrit knife edge tool for the hot roled where I can.

Stuart


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## Wreck™Wreck (Jun 19, 2016)

Have never used such a tool but imagine is is essentially a skiving process?


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## 4GSR (Jun 19, 2016)

It's unfortunate that finding good quality steel to make things out of is out of reach to most of us.  And the "quick" resource is to run to the local box store pay triple the price for a piece of steel bar that winds up having poor machinability rating compared to other steels out there.  Most of us do this and live with it.  Few places have steel service centers set up to sell material to us H-M, an most of them are not open on weekends or after 5:00pm during the week.  I have had good luck buying short lengths of material from places like Speedy Metals, but plan on spending $100-150 in order to justify shipping charges.  Here's how I buy from Speedy Metals, I buy B1117 grade material in four foot lengths.  I select diameters like 1/4", 5/16", 3/8", 1/2", 5/8", 3/4", 7/8", and 1".  This will come up to around $75-85.  Shipping will be around $25 for this bundle of material.  It will probably last my lifetime but will come handy when needed.  Since I bought this bundle of stock, I've added 1-1/4" and 1-1/2" to the bundle.  I have a lot more material than this on hand that I've collected over the years.  Some of it is left over from dad's shop when he was alive.  And if anyone needs a small chunk of material and can't afford to buy it, let me know.  I'll check and see if I have it on hand.  Most of the time I only ask you pay for shipping and make a small donation to H-M. Ken

BTW- I now have chunks of G-2 cast iron on hand that can be sliced up for making back plates for chucks.


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## AGCB97 (Jun 19, 2016)

So much great info!

I made some changes in the way I was doing things based on these replies and was able to get a good shiny finish on a piece of 1" A36 w/ minimal filing and sanding.

Thanks for sharing your time and knowledge.
Aaron

I found a local shop that says "help yourself to anything in the metal dumpster" and even has a couple of pallets inside with better smaller pieces of good metal that is not off limits. I make sure to bring them donuts for their Monday morning meeting every couple of weeks


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## AGCB97 (Jun 19, 2016)

I have two 4 jaw chucks that need back-plates for my lathe. I just started making one for the 8" chuck out of mild steel. Is this going to be OK? I also have a 10" that I want to make a back-plate for after I do the smaller one. My lathe has a threaded 2 1/4" 4 TPI spindle. I made a stub spindle as a test piece for when I start internal threading.

Ken I'm interested in that cast iron you mentioned. Would it be large enough for the 10"? The threaded portion is about 2 1/8" long


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## AGCB97 (Jun 19, 2016)

QUOTE Wreck
Can't help you if you are using HSS tooling as I haven't run a turning job with it in 30 years.

My 1920 Springfield Ideal Lathe came with about 2 gallons of carbide tooling, many with the coating still on them. Much other tooling also. I told my wife "I can hardly think of anything more to buy".         That doesn't mean I'm not trying and succeeding.


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## Wreck™Wreck (Jun 19, 2016)

[QUOTE="AGCB97, post: 405780, member: 41855"

I found a local shop that says "help yourself to anything in the metal dumpster" and even has a couple of pallets inside with better smaller pieces of good metal that is not off limits. I make sure to bring them donuts for their Monday morning meeting every couple of weeks[/QUOTE

Excellent way to go, we probably scrap 600-800 pounds of aluminum per month, rounds, flats and cast jig plate such as MIC 6,  also a good deal of 304 SS which is of course much heavier. My employer would sell you pretty much any drop for $10.00 if you walked in the door and asked nicely, if you were very nice he would probably give it to you for free.

When you walk into a working machine shop no one there is interested in your hobby project and could do without a detailed history.
This is not to disparage hobbyist projects at all, everyone that works there has a job to finish however so they will not hold your hand.

In order to get drops from working  machine shops ask for material in whole inches, if you say that you need 1 7/16 cold rolled round  because you make Artisan didgeridoo's the owner is likely to toss toss your pretentious butt right out of the building. If on the other hand you had merely asked for 1 1/2" CR bar  he may just give you 10 feet of it just to get it off of the floor.


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## 4GSR (Jun 19, 2016)

AGCB97 said:


> Ken I'm interested in that cast iron you mentioned. Would it be large enough for the 10"? The threaded portion is about 2 1/8" long



Probably not.  The material I have on hand is 6-1/2" OD.  Let me know what OD you need and length and I'll see what I can get my hands on.


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## AGCB97 (Jun 20, 2016)

4gsr said:


> Probably not.  The material I have on hand is 6-1/2" OD.  Let me know what OD you need and length and I'll see what I can get my hands on.



The total diameter of the chuck is 10 1/4". The videos I've watched make the back-plate the full diameter of the chuck. I'm not sure of the reason for this since it doesn't seem that will add any rigidity to the chuck since it is already heavy cast.

The recess on the back of this chuck is 5 9/16" and the boss around that recess is about 6 1/4". Would not a back-plate that just covered the boss and fit the recess be good enough? That is where the mount holes are. This would simplify the project greatly.


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## 4GSR (Jun 20, 2016)

Yep!  The back plate just needs to large enough to fit the counter bore on back of the chuck.  Also big enough to provide holes for the socket head cap screws to go into.  This applies to most 4-jaw chucks.  Most 3-jaw chucks require a backplate the same OD as the chuck, since the bolt holes are on the outer rim of the chuck.  I've seen a few 3-jaw chucks that have bolt holes located in the counter bore of the chuck.  So it just depends on the chuck you are needing to make a back plate for.  If you like a piece of the cast iron I have, PM me for details.


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## intjonmiller (Jun 20, 2016)

Ken, I wish I had seen your offer before about 9:00 pm last night. I just ordered a couple short lengths of hex stock 304 SS from eBay because it was the cheapest way to get what I needed to make a replacement part for my lathe (the movable shaft thing for one of the change gears). I didn't actually want to make it out of SS, but the only other options I could find for less than $20 after shipping were 360 brass and 6061 aluminum. I guess I need to learn to turn stainless at some point, so why not while I can't get a fine feed?  

I'll definitely keep your offer in mind in the future. It's very generous and helpful of you.


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## Wreck™Wreck (Jun 20, 2016)

Not to derail this thread but a bit of insight into making parts for a living.
Fridays parts




12 MM diameters made in an 8" chucker lathe

Mondays part.
12" X 10 " X 5" with a 5.187 +.005 - 0.000 bore made in a Tos 24" X 100" lathe in a 4-jaw chuck, a rod end for a hydraulic cylinder.

The milled blank weighs 150 Lb's. What a difference a weekend makes.


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## Downunder Bob (Jun 26, 2016)

FOMOGO said:


> Doing it for a living, definitely makes a difference in one's approach, and generally means stouter, and higher quality machines to do the work. On my 12" Craftsman I have also made good use of a file and emery cloth to get a good finish. I'm looking forward to eliminating some of those steps with the new to me TOS I've yet use.  The great thing about this forum, Is that you get so many different, and valid approaches to to the same issue. Mike



Always more than one way to skin a cat.

Yes I always encourage beginners to experiment with HSS tools, mess around with with rakes and clearance angles, when I was an apprentice only the senior toolmakers could have carbide tips, there were no inserts just brazed pieces on a steel shank. I experimented with HSS and found that I preferred some tools that did not fit the text book shape, but they worked for me.

Al;os make sure your tool is on center, It's better to be slightly below than above, on center is best.Also check the gibbs are as tight as possible without binding, and make sure there is no wear in head stock bearings, adjust if possible, if not replace them.


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## Bob Korves (Jul 1, 2016)

When I took up this hobby I was only using HSS tooling and turning it slowly, just to make sure I didn't break anything or do something stupid.  Over time I have found out that the first answer to a poor finish is to try to increase the speeds and feeds.  I was able to go seemingly a couple of magnitudes above where I started, and the finish just kept getting better.  Eventually I found the limit, but I learned to not give the metal time to flow and tear.  It comes off clean before it has a chance to deform.  It seems to make the metal act harder than it actually is.  I also found out that by using that approach my projects get done a lot faster.  Using a speed and feed chart is also a great way to get an idea of where to start.  Try starting about 20% slower than the chart says, and if that goes well, try speeding it up...


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