O/T LATHE TOOLS

[DavidB]

Can someone with Lathe experiance tell me what would be the advantages of using a DCMT over a DNMG when you only get 2 edges per insert insded of 4 on a Neg tool?

 

Im new to Lathe programing so be gentle with me.

 

[pno home]

I use dnmg for finishing or semifinishing it' very good with PDHNL tool from SECO It's a nice combination for OD turning. You have posib. to turn from 1 shot OD and faces.

And It's good for ID finish for big diameter.

I use DCMT for small diameter for finish pass.

Sometimes I use CCMT for this if I have a deep hole.

[McRae]

The difference is the clearance angle behind the insert. The DNMG is 90 degree shoulder behind the cutting edge and the DCMT gives a 7 degree clearance behind the cutting edge. Sure the DNMG is tipped in the holder to give net clearance but the DCMT will give much lighter cutting pressure.

 

Size and clamping are the other advantages over the other - the "C" will allow use in smaller tools and the "N" is for use on the large ones.

[mike_f]

Some materials like a positive cutting edge, the dcmt gives you a positive cutting edge, a weaker cutting edge but sometimes necessary. for finishing soft or gummy materials a positive cutting edge is sometimes needed. HTH

[DavidB]

thx