Aluminum specific threading inserts

I’m curious what others have found for machining 6061 and 7075 aluminum metric threads 12-30mmx1.0,1.5 pitch. All OD threaded features. I’ve tried some uncoated full profile Iscar and Vargus inserts. I’m running things as fast as I can. Machine is an early 90 model Okuma LNC-8 Cadet. I get a little tearing on the threads. Some come out amazing, but not always. Will be running quantities in the 100’s to low 1000’s.

I re run the chamfer and full depth of threads in a single pass afterwards and it cleans up well. I’ve changed up the program quite a bit trying to improve machining strategy. I feel like I’ve got the best results with what I have to work with.

Looking for some options to consider trying to get better results. Will be a bar pull operation and want these to run well where I don’t have to deburr all by hand.

Thank you in advance.

chamfer and bore with boring bar,
thread part
run drypass on chamfer bore again
then 2 pass's on threads.
comes out clean every time.

if your spindle liner isnt close to the size of your bar size your going to have some small differences in size.
coated or uncoated either one works fine I like uncoated. I am not keen of full profile threading inserts but thats just me.

Delw said:

chamfer and bore with boring bar,
thread part
run drypass on chamfer bore again
then 2 pass's on threads.
comes out clean every time.

if your spindle liner isnt close to the size of your bar size your going to have some small differences in size.
coated or uncoated either one works fine I like uncoated. I am not keen of full profile threading inserts but thats just me.

Click to expand...

You’re the second person to say the same on full profile inserts. I’ve used both and had good results. I like hearing other people’s results and opinions. I haven’t threaded a million different threads to have a knowledgeable enough opinion my self.

We use full form threading inserts for the vast majority of our needs, and find them greatly superior to anything else in all but a very few or our applications. We had some gummy 6061 where we use a TNMC insert, other than that, full form is the way to go for us. Sometimes there are clearance issues, and a TNMC will get where a full form wont.

Gobo said:

We use full form threading inserts for the vast majority of our needs, and find them greatly superior to anything else in all but a very few or our applications. We had some gummy 6061 where we use a TNMC insert, other than that, full form is the way to go for us. Sometimes there are clearance issues, and a TNMC will get where a full form wont.

Click to expand...

Any brand inserts specific that you’ve noticed a difference with?

clayton said:

You’re the second person to say the same on full profile inserts. I’ve used both and had good results. I like hearing other people’s results and opinions. I haven’t threaded a million different threads to have a knowledgeable enough opinion my self.

Click to expand...

Ive used them for 1/20 pitch threads, made a good thread. my only problem with them is I like to control the minor/major and the thread profile separately. plus the fact that your doing lot of profile with one tool. hitting flanks and major/minor as same time. the seem kinda week in my mind if you have a fast pitch deep thread and prone to taper and chatter on smaller longer threads

the other reason is if you run different threads all the time you will need a bunch of different inserts

Delw said:

Ive used them for 1/20 pitch threads, made a good thread. my only problem with them is I like to control the minor/major and the thread profile separately. plus the fact that your doing lot of profile with one tool. hitting flanks and major/minor as same time. the seem kinda week in my mind if you have a fast pitch deep thread and prone to taper and chatter on smaller longer threads

the other reason is if you run different threads all the time you will need a bunch of different inserts

Click to expand...

99% of the time there is not really any good reason to want to control the minor/major/PD separately. I cut a lot of threads, and I always prefer a full profile insert unless there is some real issue with doing so. You get chamfers and radii in all the right places and don't need to perform any additional finishing the vast majority of the time. The job gets done quicker because there is less to do, it's that simple.

Vardex have a polished aluminium specific grade called VK2P.

That said, most of the problems I've encountered single pointing aluminium boil down to lubricity and BUE. If you're using a soluble oil that's only marginal in aluminium you will have poor results compared to something that is engineered specifically with aluminium in mind.

My experience is that 6061 sometimes comes in very gummy, and that's the only time we have any issues threading. We always use cresting inserts, and generally re run the chamfers backwards after threading to get most of the burr

vegard said:

My experience is that 6061 sometimes comes in very gummy, and that's the only time we have any issues threading. We always use cresting inserts, and generally re run the chamfers backwards after threading to get most of the burr

Click to expand...

I re run the chamfers too, but haven’t run them backwards. I will try that.

gregormarwick said:

99% of the time there is not really any good reason to want to control the minor/major/PD separately. I cut a lot of threads, and I always prefer a full profile insert unless there is some real issue with doing so. You get chamfers and radii in all the right places and don't need to perform any additional finishing the vast majority of the time. The job gets done quicker because there is less to do, it's that simple.

Vardex have a polished aluminium specific grade called VK2P.

That said, most of the problems I've encountered single pointing aluminium boil down to lubricity and BUE. If you're using a soluble oil that's only marginal in aluminium you will have poor results compared to something that is engineered specifically with aluminium in mind.

Click to expand...

I’ve had the Vardex rep over before. I will try those inserts. I know machining 6061 is the biggest pain having the gummy properties. I’m using Qualchem Xtreme cut 250c at 7 brix.