ID Threading damage

[srpttech]

Hi,
We trying to stabilize the 18 NPT 1/4' ID threading operation, but when we start do threading operation we noticing some abnormal voice while threading and threading insert getting damaged on both top and bottom side,

Please help me some body
thanks
gopi

[shay z]

can you give more details like material, tool, speeds and cutting depth?

is you can write here the cicle G code it even be better.

[Motherlode97]

Sorry but you must use a tap for pipe threads.

ML97

[shay z]

why must use tap? i am making threads from 3/8 NC and up to 3" BSPT with vardex tools.

[Motherlode97]

NPT pipe threads are tapered and not possible to interpolate correctly on Hurco. It may be possible with a postprocessor which would output point to point helical moves in three axis along a taper. ( 3/8 NC is a std straight thread.)
Hope this helps.

ML97

[shay z]

I am not doing it with cad/cam system but writing it directly on the controller (all BSPT threads are tappered).

[srpttech]

can you give more details like material, tool, speeds and cutting depth?

is you can write here the cicle G code it even be better.

Hi,

Details as fallows

Material:-SS-316
Threading Size-18 1\4 NPT
Pre- machined Bore size:-
Dia Minor Large=Dia 11.9mm
Dia Minor Small=Dial 11.3mm
Thread length required=11.2mm
Threading Insert Grade= Vardex make VM7 grade 6.0IR-18N
Tool Holder= Local make (professionals in tool holder making) 15mm length
Machine Type= Lokesh machines Limited, India model TL-20 (www.lokeshmachines.com)
Parameter as fallows
Rpm-1200
G97S1200M03
G76P030060Q50R10
G76X12.55Z-12.5P564Q50R45F1.411

even i tried with G32 but result is same
if you want i can send images of insert brakege

[shay z]

why arenwt you using 6.0SIR27NPT insert?

please send images.