Difference between cutting radius on DCMT inserts

[ee02004]

Good morning,

I have a small proxxon pd230 lathe and a couple months ago I've bought a couple of toolhoders DCMT 0702 inserts on ebay. These toolholders came with a set o inserts of unknown origin. Since I have to buy new inserts, I need to know what will be the difference between using DCMT 070202 and DCMT 070204 inserts?
What will be the main difference between the two cutting radius?

 

[Nick Hulme]

0.2 Tip Radius
http://www.iscar.com/eCatalog/Item.aspx?cat=5550299&fnum=868&mapp=IS

0.4 Tip Radius
http://www.iscar.com/eCatalog/Item.aspx?cat=5508098&fnum=868&mapp=IS

A larger tip radius can help in achieving smooth surface finish in some materials

 

[Hopper]

On the other hand, larger radius can induce more chatter on smaller, less rigid lathes.