Author Topic: Indexable carbide tips  (Read 565 times)

Offline Gas_mantle

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Indexable carbide tips
« on: May 14, 2018, 05:04:17 PM »
While at the Doncaster show a few days ago I wanted some carbide tips for my indexable lathe tools, the guy I bought from asked if I was interested in the old style or the new sooper dooper ones ?

To me I kinda thought carbide tips are pretty much the same but he said these new ones give a much better mirror finish although they don't like cast iron or interrupted cuts and don't last quite as long as the old style  :headscratch:

I decided to buy a few of each and wondered if anyone else has heard of these new(?) tips ?



They seem razor sharp and have a mirror finish to them. Here they can be seen against the old style.



I haven't had chance to try them but will give them a go tomorrow.

Offline jadge

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Re: Indexable carbide tips
« Reply #1 on: May 14, 2018, 05:41:05 PM »
The "old" style tips look like standard inserts designed for ferrous materials, and possibly interrupted cuts. The "new" style look like standard polished and higher rake inserts designed for softer materials, in particular aluminium alloys.

To describe them as old or new style says to me that not only were the cows lying down the bulls were sitting as well.  :o

Andrew

Online Jasonb

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Re: Indexable carbide tips
« Reply #2 on: May 14, 2018, 06:29:18 PM »
I'd agree with Andrew you just have tips for two different uses although the Shiny **GT ones can be used on steel and stainless. The salesman was right when he said they won't last as long when used on these materials, they are handy on long slender items where the "blunter " edge of the **MT inserts can deflect the work away from teh tool and also encourage chatter.


Did you get the full code for the inserts as it is the last few letters and numbers that can make all the difference not just the basic shape, size and corner radius, see my posts about the 50mm face cutter as an example. The "old style" ones you have there also look to have quite a large tip radius which I find don't work so well on lighter machines.

I also find the **GT ones work very well on brass and bronze not just aluminium.
« Last Edit: May 14, 2018, 06:33:25 PM by Jasonb »

Offline Gas_mantle

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Re: Indexable carbide tips
« Reply #3 on: May 14, 2018, 06:39:58 PM »
I don't have the code for the tips, I'm a bit unsure what the numbers and letters mean so I just asked for general purpose tips. I bought a few standard ones and a few of the new(?) ones to see what the difference is.

Offline Florian Eberhard

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Re: Indexable carbide tips
« Reply #4 on: May 14, 2018, 07:07:45 PM »
I also find the **GT ones work very well on brass and bronze not just aluminium.

And if you have a coated version, you can even use them for light cuts on stainless steel (also for normal steel)

Peter, google for the "carbide insert idendification chart". That will help to identify the inserts you have there.

For example a CCGT 060202 means the following:

The first "C" says what shape your insert has, the second "C" tells you what cutting edge clearance you have, the "G" tells you which tolernaces your insert is made within and the "T" what style of chip breaker you have.

The "06" tells you the size of your insert which is done by the inscribed radius, the following "02" tells how thick the insert is (which is usually connected to its size) and finally the last "02" is the corner radius in 0.1mm so a "02" at the end means your corner radius is 0.2mm.

Cheers Florian
ps: Mitsubishi has a quite good description of that "Code" on its homepage:
http://www.mmci-carbide.co.in/technical_information/tec_turning_tools/tec_turning_insert/tec_turning_guide/tec_turning_identification

Offline Gas_mantle

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Re: Indexable carbide tips
« Reply #5 on: May 14, 2018, 07:34:31 PM »
Thanks Florian, the table is useful  :)

I guessed that the letters and numbers referred to the tip geometry etc but wasn't sure how it worked and hadn't seen the table before. I have a few indexable tools but could do with a few more once I decide what I need  :)


Offline AdeV

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Re: Indexable carbide tips
« Reply #6 on: May 14, 2018, 07:48:29 PM »
I've got quite a few of the "shiny" type (bought from Chronos), and they are spectacular on aluminium, and damn good on steel if you take it easy with the cut depth & don't let the temperature get too high.

The reason they don't like interrupted cuts is their sharp edges makes them weaker, and more prone to chipping (and carbide is already highly prone to chipping on interrupted cuts).

The "old style" that you pictured are probably TiAN (or something similar) coated, that's what gives them their gold colour. They're also quite "blunt", i.e. ideal for taking heavy cuts in steel. Remember that most carbide inserts are designed for industrial use, where time = money; so if you can hack off 1/4" of steel from a piece in one cut, that's a good thing. Most of us hobbyists - even those of us with industrial sized machines - would probably baulk at a 3mm cut depth in steel...
Cheers,
Ade
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I'm just a poor old man. I have no time for law-breakers. My legs are grey. My ears are gnarled. My eyes are old and bent.