# Deep Boring



## thestelster (Jul 28, 2022)

I had to bore out a piece of AL6061 to 0.740".  Used a 5/8" carbide boring bar.  6" depth, that's 9.6:1 ratio.  No chatter,  670rpm@0.005ipr.  It was a pretty tight fit!  Finish isn't great, but doesn't need to be on this project.


----------



## Susquatch (Jul 28, 2022)

thestelster said:


> I had to bore out a piece of AL6061 to 0.740".  Used a 5/8" carbide boring bar.  6" depth, that's 9.6:1 ratio.  No chatter,  670rpm@0.005ipr.  It was a pretty tight fit!  Finish isn't great, but doesn't need to be on this project.



Boy, that's a tight fit! Nice job!

For some reason my pants don't fit right whenever I do stuff like that.

Guessing some of the finish observation was the result of swarf bunching up behind the bar.

Is the boring bar carbide or just the insert?


----------



## thestelster (Jul 28, 2022)

Susquatch said:


> Boy, that's a tight fit! Nice job!
> 
> For some reason my pants don't fit right whenever I do stuff like that.
> 
> ...


It's a carbide shank with coolant hole.  I blow compressed air through the hole to clear the chips.


----------



## Brent H (Jul 28, 2022)

Nice work!!


----------



## Susquatch (Jul 28, 2022)

thestelster said:


> It's a carbide shank with coolant hole.  I blow compressed air through the hole to clear the chips.



Ah, I see! Very cool! Does the air blowing through the shank act like a venturi to pull extra air through the tube too? Or does it just go everywhere?


----------



## Proxule (Jul 31, 2022)

Try dcgt or ccgt inserts, sharper and allows for shallower DOC.
They're intended for aluminum but do nice in steel as well
gluck


----------



## thestelster (Jul 31, 2022)

Proxule said:


> Try dcgt or ccgt inserts, sharper and allows for shallower DOC.
> They're intended for aluminum but do nice in steel as well
> gluck


I've never tried those inserts.  I'll have to give them a go.  But how long do they last on steel?


----------

