# Experience Turning And Parting 304l And 303 Stainless Steel



## TonyL (May 23, 2016)

Does anyone have experience to share turning the above on their Chinese 7x or 8x lathe?

I wonder if they are rigid and powerful enough.

I want to make these bushings starting with .625 SS rod.


https://www.lazerlinez.com/collections/bushings/products/tbc-bushing-cigar-pen-kit


Thank you for reading.


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## TOOLMASTER (May 23, 2016)

good carbide is best..


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## TonyL (May 23, 2016)

Thank you. Does that mean that you have used a lathe described above to turn and part that SS?


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## TOOLMASTER (May 23, 2016)

i try to cut it fast on small pieces before it work hardens.. in general ss can be a pita, but it is doable


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## TOOLMASTER (May 23, 2016)

are the bushings to hold the pen or part of the pen?


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## Garththomas (May 23, 2016)

I recently parted  a piece of 9/16dia. stainless on my G0768 with a 1/8' hss home ground blade with success. Power was no problem but I should have tightened the cross slide and compound before starting because it was a very noisy experience. I know my blade is a little to wide but I need that width for grooving another project. I was surprised at how aggressive a cut I had to make for good results, its not for the timid as now I've found on other cuts.


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## TonyL (May 23, 2016)

Thank you both. The bushings are to hold the pen blank material between centers on a wood lathe. Sounds like something suited for the more powerful/heavier lathe. Thank you again.


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## TOOLMASTER (May 23, 2016)

for the money if you just need a set.. i would just buy them.


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## TonyL (May 23, 2016)

u r right, but i want to make them, turn, thread, and bore metal pens. My BIL's 3 brothers are all machinists. They will and have made me as  many as I want for free. I thought bushings were a good starter project. I didn't now SS was a PITN. Thanks for the feedback.


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## DSaul (May 23, 2016)

I turn a lot of 303 on my old South Bend 405.  It doesn't suffer from the same work hardening issues as 304.   I use cemented carbide cutters, mostly because I'm too lazy to grind HSS, but HSS should cut it with no problem.  I see no reason why your lathe wouldn't be up to the job.


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## Garththomas (May 23, 2016)

I guess thats what I meant to say, if your using the appropriate cutter and your machine is properly adjusted it shouldn't be too big a job for a small lathe. 
I"m not  deterred from doing it again, just a little wiser.


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## Wreck™Wreck (May 23, 2016)

TonyL said:


> Does anyone have experience to share turning the above on their Chinese 7x or 8x lathe?
> 
> I wonder if they are rigid and powerful enough.
> 
> ...


There should be no problem doing the turning.
If done dry (no coolant) with inserted carbide tooling designed for steel/stainless. Turn it at 300-600 RPM's at a minimum .025 DOC and .010 or more feedrate for roughing, if done completely dry the material will stick to the tool and cause a fuzzy surface on the part, a 20% mix of water based coolant in a spray bottle works well to stop this. Finish turn at the same speed or faster at .004 to .008 DOC and .004-.005 feed with lots of coolant sprayed on it.

As far as the parting goes power feed it at .001-.002 per revolution at say 250 RPM's, it is a small part and should come right off with a dull finish, much coolant is required for this operation however as the chip will be stuck in the slot.

Good Luck


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## royesses (May 23, 2016)

When I first got my 7x10 my Son wanted it to make vape parts. I ordered some 304 stainless tubing .125 wall 1" diameter. We turned it and threaded it with HSS tools. AR Warner tools worked the best. Parting was difficult on the basic 7x10 with no modifications. Parting was at about 30 rpm with a very sharp HSS parting blade on an 0xa Tormach qctp. Since then I have added angular contact bearings and a reduction pulley and belt kit. I tightened up all gibs and added an LMS carriage lock. I still start the parting at 30 to 40 rpm with a lot of oil, but the reduction pulley kit gives more torque and powers through the cut. As the diameter gets smaller I up the rpm a little. The swarf comes off in little curls shaped like a 6. When you part you need to lock the carriage and possibly lock the compound by tightening one of the gib screws. Once you get the procedure down pat for Your lathe it actually is fun to part. Drip oil on the cut and if it starts chattering feed the tool in until the chattering stops. Then keep it going steady.  I'm not trying to scare you off, just letting you know what worked for me. I used an LMS 1552 Cut-Off Blade P1X.

Roy


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## TonyL (May 23, 2016)

Thank you all very much. I will heed all advice!


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## RCWorks (May 24, 2016)

These small lathes don't like to part in forward, use a good sharp carbide parting tool in the holder upside down, run the lathe in reverse. These small lathes are wet noodles but most of the problem is in the tool post mounting. The slides are just too small... take it slow, lube it and you'll get through it. If you start now you can shave and have breakfast in tomorrow morning when you get the first one done...

It's a slow process on my 8x12 Central Machinery mini lathe. I have been thinking about making a tool holder to eliminate the compound slide in an effort to get better parting.


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## TonyL (May 24, 2016)

Thank  you. I watched a YT on reverse rotation parting. I am thinking a Precision Matthews may be a better choice for me. I/my friend will be trying this on his HiTorque 8.5 x 16 on Saturday. Chris at the LMS said it would work great. Thanks again.


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## RCWorks (May 24, 2016)

TonyL said:


> Thank  you. I watched a YT on reverse rotation parting. I am thinking a Precision Matthews may be a better choice for me. I/my friend will be trying this on his HiTorque 8.5 x 16 on Saturday. Chris at the LMS said it would work great. Thanks again.



While I have had my 8x12 for about 10 years and I can make with the machinist magic of press fit etc. I wish I would have bought at least a South Bend 10 inch. But back then it was a new hobby, I had taken some shop classes in jr high school and figured since model aviation was my reason for use that small was great... Now I make accessories for these bench top machines and I see that small s great if you have all day, when it comes time to make a serious cut size matters.

When I make enough selling accessories I will be getting a 10 inch, hopefully a South Bend and maybe a Bridgeport for the main reason it would take fewer passes and make me more profitable.

Best of luck with your new lathe, may it be as good as you need it to be.


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## mikey (May 24, 2016)

Tony, stainless is not a hard material; it is easier to turn than some of the common things we turn. The problem with SS is that it work hardens and this occurs when cutting temperature rise at the point of cut. When this occurs it becomes difficult to take small depths of cut (like finish cuts) until you cut under that hardened surface, at which point the tool will cut well again. 304 SS will work harden much faster than 303 SS so the material you choose will affect your results, too.

It isn't so much the size of the lathe that determines how well it will cut SS. Rather, it is the rigidity of the set up and the cutting tool geometry you are using that is as, if not more important than, the lathe itself. This applies to turning, boring and parting. Heck, even a small lathe like a Taig or Sherline can handle these operations with no problem at all. Others have suggested carbide tooling but SS responds better to a sharp HSS tool with the right tip geometry on smaller lathes in non-production settings. At the speeds available on hobby lathes, HSS will also finish better. For that matter, cobalt tooling will cut SS just as well and last longer before dulling.

In the size class of lathe you are looking at you will find that sharp HSS/cobalt tooling will work better in almost all cases. The problem with these tools is that you have to learn to grind them, and not everyone is willing or able to do that.


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## TonyL (May 30, 2016)

Thank you very much. I did make my first bushing with 304L on Saturday on my friends 8.5 x 16 Sieg. He used HSS. I didn't look hard to sharpen. It worked fine. It seems like the lathes in the 2k and under range aren't taken too seriously, but apparently do what I want them to do. Thanks again to all!


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