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3xd or 4xd Insert drill length?

mmurray70

Stainless
Joined
Jan 11, 2003
Hey guys im picking up a sandvik 880 drill 1.25" dia. Trying to decide 4x or 3x. We do mostly jobshop work, so times we could use the extra length. Also would be handy at times to be able to rough bore with it to make starter hole for larger bar.

Can you bore with a 4x drill or would 3x be the limit? Can the 4x do it all or do i need to choose between being able to bore and having extra length.
 
I haven't had the best of luck trying to use it as a boring bar, even on 3D, but "drilling" oversize the first time through works fine.


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Think Snow Eh!
Ox
 
880 insert drills don't allow for very much X-axis offset when drilling into solid material. Look at Seco drills for that. I think there is only one model that allows for a very large X-axis offset when drilling. Be prepared to be shocked at their price. If I remember correctly, it is the SD70 drill. An SD52 runs similar to the 880 Sandvik.

I got out of ordering tools many years ago. I just know we recently replaced an SD70 with an SD52 drill (off ebay) because the boss wouldn't pay the $600 or so for the SD70. Now I have to modify all our programs that used that particular SD70 drill.

EDIT: K-Tool makes an insert drill mill. As the name might hint at, it gives a very nice flat bottom thus you can bore to a shoulder with it. I use them in aluminum and 303 SS to eliminate a rough boring bar. SFM is slower than the previous mentioned drills. Don't know if I would use it to bore in tougher materials. Haven't tried. Also kind of expensive, but what isn't these days. I'm currently running 5 of the .875 K-Tools in 3 lathes.
 
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Insert drills make expensive and crappy boring bars IMO. Just saying................
I'm with Dan on that. I don't have any experiences with Sandvick drills as I use Komet via their ABS connection. The outer insert does Q up perfectly in X on a 45 slant bed lathe, so I use it for the occasional truing up or making of soft jaws. But as a rule I tend to buy the tool for the job. And like most things in machining, the shorter the tool the better.
 
Me personally I'd go for a 2.5x or 3x drill from Seco. I've occasionally done X offset drilling so that way I can skip the rough boring operation and go right to finish. As others above have said, insert drill kinda suck when it comes to boring compared to an actual boring bar. Offset drilling allows you to "bore" a hole larger than drill nominal without having to actually use it like a bar.
 
Pretty sure OP is asking about using this in a lathe application.

While a 4xD drill can't be pushed quite as hard as a 3xD, I've never encountered a situation where a few minor parameter tweaks wouldn't make the 4xD drill work.

As for boring out the ID after drilling, in order to provide clearance for the boring bar, again the 4xD will work at reduced parameters.

We do mostly jobshop work

4xD.
 
Insert drills make expensive and crappy boring bars IMO. Just saying................
You use what you can when you have all 24 stations already full of tools. Some using double holders. So far I've only had to use them in aluminum, brass and 303 SS. Really wouldn't care to bore with a drill in tough materials. Like you said...expensive to ruin.
 
Thanks for the help guys. I didnt realize you could intentionally drill off center with these. thats pretty cool. Makes sense too about it being a very expensive and shitty boring bar.

I ordered 4xD and will try not to use it for boring unless im out of holders. Thanks!
 
I don't agree with most of the people here saying that insert drills are not good boring tools. I open up bores with insert drills, in all kinds of materials fairly often without any problems at all. It's just a matter of following the manufacturers recommendations for using the outboard insert to take boring passes.
 
I don't agree with most of the people here saying that insert drills are not good boring tools. I open up bores with insert drills, in all kinds of materials fairly often without any problems at all. It's just a matter of following the manufacturers recommendations for using the outboard insert to take boring passes.
What brand of tool and what length?
 
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I don't agree with most of the people here saying that insert drills are not good boring tools. I open up bores with insert drills, in all kinds of materials fairly often without any problems at all. It's just a matter of following the manufacturers recommendations for using the outboard insert to take boring passes.
We're not saying it can't be done, we're basically saying it's not the best way to do it.
 








 
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