Insert recommendations for good chipbreaking?

[Jelly_Sheffield]

For the 30-50 use the WNMG insert, rpm about 1000, feed about 0.3mm/rev and say 1.5mm DOC (3mm overall) and see what it is like.
Personally not keen on the WNMG as swarf can get trapped in behind and mar the finish, always happens on the last cut as well

Will see if I have any carbide WNMG inserts and give those parameters a try.

Running that slow will just trash the Cermet inserts.

 

[northwest]

En16 in decent diameters seems to be hard to source at present. The opposite of a year ago when en16 was easy and en24 impossible to source

Modern en8 is lower in carbon hence it’s not as nice to machine as it once was and hardening contractors won’t guarantee success with it

TBH I think we are chin deep in the poo when it comes to some steels, the quality is just not there. I have noticed that some materials that I know for a fact come from (for instance) Spain machine far better than the equivalent grade material bought here in the UK. If anyone has any ideas as to why this should be I would be very interested in hearing. Recently I have had some tube to machine (okay barrels) and the Spanish (Bergara) have been far superior to the German equivalent. The German items appear to have been made from the finest recycled bedsteads (Trabants) whereas the Spanish items have finished beautifully. The German items having cost twice as much!