Need Boring Help

[mikey]

From what little I could find on machining cast stainless steel, it looks like that stuff is tough on inserts. I would have to defer to Dave. It sounds like he has a lot of experience with that stuff.

Still, your insert looks to be the equivalent of a CDCD505 insert with a 0.007" NR. It should have bored that wheel. I don't know what the cutting speed of cast SS is but most stainless is pretty high, up around 500sfm or so. I wonder if a higher speed would work better? I've bored a lot of stainless but it has been 303, 304, 316 or 416 - never did cast SS.

Before I destroyed more inserts, I would contact Widia and speak to one of their engineers.

 

[Janderso]

Is the material magnetic?
Stainless bolts are non ferrous, in my experience.

 

[rgray]

1/2" endmill and bore remainder might work?

 

[ddickey]

Bore is 10mm- needs to be opened to 12mm.

 

[rgray]

The job is to bore out the center bore from 12mm to 14mm.

I was ill informed.?

 

[ddickey]

I also need to drill and tap M4-.7 for a grub screw as the keyway will be all but gone after boring. Not sure how to deal with the burr as I have no deburring tool for that type of operation.

 

[mmcmdl]

Is the material magnetic?
Stainless bolts are non ferrous, in my experience.

300 series stainless is non-ferrous . What about all the 400 series and customs ? If you can heat treat it , it's ferrous .

 

[mmcmdl]

Go with a solid carbide bar if you need to . I use Kennemetal top-notch bars usually or micro grains in small stuff as that bore .

 

[ddickey]

My bar is carbide. I may punch the hole out first with a 29/64 drill then finish with the boring bar.

 

[mmcmdl]

That drill sure won't like that keyway !