[Sierra Nevada]

I am trying to part off some 304stainless .625 rod. Very close to the chuck. I'm using an Iscar holder and insert. Question is What RPM's do I start with. I've tried CSS with .003 IPR, 140sfm and 1200RPM as the limit and I'm burning through inserts and getting a red hot shmeared chip coming off. I've tried to fiddle with the numbers. I've gone down to .0003 IPR and that is just soooooooo slow. I've seen people program .004 IPR till they hit .5" then .003 IPR till they hit .3 then .002 and so on, but There has to be an easier way. Why is this so complicated? I figure by now there would be some sort of brain dead easy settings to go with, but I can't even get close to something I'm happy with. Any help will be appreciated. I'm using Gibbscam, and can use Bobcad if I want to dust off that piece of crap. THANKS !!!

[gbpacker40]

I am trying to part off some 304stainless .625 rod. Very close to the chuck. I'm using an Iscar holder and insert. Question is What RPM's do I start with. I've tried CSS with .003 IPR, 140sfm and 1200RPM as the limit and I'm burning through inserts and getting a red hot shmeared chip coming off. I've tried to fiddle with the numbers. I've gone down to .0003 IPR and that is just soooooooo slow. I've seen people program .004 IPR till they hit .5" then .003 IPR till they hit .3 then .002 and so on, but There has to be an easier way. Why is this so complicated? I figure by now there would be some sort of brain dead easy settings to go with, but I can't even get close to something I'm happy with. Any help will be appreciated. I'm using Gibbscam, and can use Bobcad if I want to dust off that piece of crap. THANKS !!!

The RPMs seems really high. 500-625RPM 150-175sfm and .002-.003ipr. One thing cutting off on 304 is to make sure you're flooding the hell out of the insert or you'll be burning right thru them. Also make sure you aren't cutting it all in one pass, your groover should retract every .050-.125" to not only release chips,but to cool both the metal and insert.

[okumamaster14]

I would suggest not using CSS when the cut off tool gets to the smaller diam. it speed up to fast. I would start your rpm around 250 and your feed around 2.5ipm. From my expirence it's best to start slow if your not sure and work your way up. We use Iscar a lot and we love the blade and block here.

[NodecoMachine]

I prefer G97. After I switched from G96 I noticed a big difference in insert performance. I never retract when parting off, espesially a .625" diameter bar. Start with a RPM of 700 and make sure you have ample coolant flow. .002 IPM is a good starting point .078-.125 wide insert. How wides your insert?

[Sierra Nevada]

I prefer G97. After I switched from G96 I noticed a big difference in insert performance. I never retract when parting off, espesially a .625" diameter bar. Start with a RPM of 700 and make sure you have ample coolant flow. .002 IPM is a good starting point .078-.125 wide insert. How wides your insert?

The insert is .160 Iscar, GFR4-8D IC354

[NodecoMachine]

Have these parts running smooth? If so, what'd you settle on? If your still having trouble, give us more info on what size lathe and such you are using... (Coolant and so on) also check that the insert is on spindle centerline. That's 1 of the most overlooked yet very important things when parting IMHO.

[Sierra Nevada]

Have these parts running smooth? If so, what'd you settle on? If your still having trouble, give us more info on what size lathe and such you are using... (Coolant and so on) also check that the insert is on spindle centerline. That's 1 of the most overlooked yet very important things when parting IMHO.

Insert is mentioned above. Oscar .160 wide. I've started to experiment with pecking and slowing down the spindle, but no concrete judgement has been reached. I'm using oil as my coolant and the coolant is right on insert.

[NodecoMachine]

Brushing the oil on or flood? This on a manual machine? What size machine? .160" is a wide parting tool for small work... Have a smaller blade? .160" just puts a lot of pressure on everything so you need a very rigid setup on a decent sized lathe

[Sierra Nevada]

Brushing the oil on or flood? This on a manual machine? What size machine? .160" is a wide parting tool for small work... Have a smaller blade? .160" just puts a lot of pressure on everything so you need a very rigid setup on a decent sized lathe

It is a Hitachi Seiki HT23 2 axis CNC lathe. Coolant is flowing right on the blade, OIL is the coolant. I will purchase a smaller parting blade, hadn't even thought of that. Thanks!

[Sierra Nevada]

ISCAR,

[redbaron88]

First of all I hate stainless it's an awesome material but it sucks cutting it. Having said that you should be running 75sfm with a max of 600rpm. Which is gonna run 600 the whole time at .625 dia so you could just g97 in this particular case and feed at .002per rev with no pecks. Just FYI I never peck unless parting off a big diameter piece which I try not to do

[Nicecutt]

First of all I hate stainless it's an awesome material but it sucks cutting it. Having said that you should be running 75sfm with a max of 600rpm. Which is gonna run 600 the whole time at .625 dia so you could just g97 in this particular case and feed at .002per rev with no pecks. Just FYI I never peck unless parting off a big diameter piece which I try not to do

My experience with 304 stainless is that its very gooey and sticky and no matter what speed or feed I used had not good results and parting in this material and facing to the center is a terrible operation with terrible tool life. I have recommended to my clients to use 316 and they have never looked back, the extra cost was little and the gain was tremendous and 304 is regarded as poor mans stainless. Even with tip drills its a nightmare 316 is like butter and if you do have do drill 304 I would use a HSS Cobalt drill. Best of luck. Cheers Cosimo