On Tue, 14 Feb 2012 11:07:05 +0000 andy pugh <[email protected]> wrote:
> On 14 February 2012 09:09, Mark Cason <[email protected]> wrote: > > Can anybody recommend what type and shape of insert to use to > > turn a 2" piece of pre-hardened 4140? > > > How hard is it? > I have found that harder steels give a better finish anyway, and with > a small cut and a huge surface speed CBN tipped inserts work nicely. > You probably want to use a tailstock for rigidity. > > Look at Youtube for examples of "hard turning" and eBay for > individual inserts. > Kennametal recommendation: < Rc 48 fine finish KT315 85 degree insert -11 very fine finish -uf fine finish starting conditions 680 sfm ( range 600 - 900 ) 0.0015 - 0.006 /rev doc .003 - 0.03 right out of the Kennametal "lathe tooling" a useful book to have on the shelf. From what I can tell CBN works very well above Rc 48 but I have no experience. Dave ------------------------------------------------------------------------------ Keep Your Developer Skills Current with LearnDevNow! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-d2d _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
