inconel 718

[Santa Fe]

Have anybody cut inconel 718. I have no problems with turning it but a couple of years ago I had a lot of trouble drilling it. Does anybody knows an effective way to drill and tap thru inconel?

 

[Hardmill]

Cobalt.

 

 

PEACE

[robk]

Holes close right up. We drill, size mill and ream if needed. Then we threadmill...

[robk]

Oil based coolants still work best, but not really much of an option on the new machines. We use water soluble coolants and use Kennametals SE drills with coolant-through option. Keep the SFM low.

[Guest]

Sulfur Oil based lubricant, carbide and low SFM carbide tend to be in the 75 - 90 SFM

 

Threading Milling in inco 718, while I have not do it yet, if it was large enough I would at least attempt to threadmill it.

[Santa Fe]

the holes I'm talking about are M10 x 1.5 - 1.051 deep and M12 x 1.75 - 1.276 deep. I read about using heavy lubricants and using cobalt drills at 28 sfm and .0013 ipr at then mill to size.

 

also have anybody knurl on same inconel 718???

[Guest CNC Apps Guy 1]

I have in the past, when drilling high nickel alloys ground one flute on a drill so that it cuts a little oversize, this keeps the hole from closing up on the drill and snapping it off. As to how much and what angle? Dunno what to tell you, just know you want to cut is oversize a min. of .001" because you want good fluid flow and because it's so gummy/mushy it WILL close back up on itself a bit.

 

Knurling 718 ... sucks to be you

[john316]

.

 

I've had better luck drilling Inconel with regular high speed drills. The high speed is able to flex a little while drilling where the cobalt will break.

 

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[Goldorak]

+1 for the kennametal drill

 

but i never tap inconnel

 

for knurling try to cut it instead of rolling it

i know that some cutting tool exist for knurling

[88Matt]

quote:

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Sulfur Oil based lubricant, carbide and low SFM carbide tend to be in the 75 - 90 SFM

---

This has worked best for me except maybe use even lower sfm like 50. I last had to drill about a 7/16" hole 2" deep. peck drill .500 deep, retract and pause. peck drill next .500 deep and pause, etc. then used a solid micrograin carbide straight flute flat bottom cutter to clean up the hole. u WILL get taper.

 

HTH

[Santa Fe]

Thank you all