metric thread cutting

[toolmaker_79]

hi guys i was a tool maker before,and changing in to cnc machining,i was trying to machine a 56 mmx5.5 pitch thread on a 30 mm thick job using a single point thread cutting insert.can any one help me with how to programe it using g2 and g3 codes.speed and feed rates.and how many pases to finish the entire thread depth.i am using a fagor cnc mill.can any one help me with this,thanks to all

[Kiwi]

Assuming this is a internal hole.
You could use G03 Helix. To climbmill you need to start at the bottom of the hole.
eg.
G00 X0 Y0
G00 Z-30
G41 G01 X28 Y0
G03 X28 Y0 I-28 J0 Z3 K5.5
G40 G01 X0 Y0
Note: You need to move Z 33mm to complete last turn.

[toolmaker_79]

thank you very much for u r help kiwi,i will give it a go with this programe,i think i might do it in couple of pases.thanks again

[Kiwi]

If your cutter is large enough to cut the full depth I would think you should be able to do one pass. I've never cut a thread as coarse as 5.5 pitch so not specking from experience.
Just to make sure I've put you right, suggest you do a trial.
Cheers.