Indexable drill for 1.00" diameter holes

[Fudd]

I have a job for some 1.00" +.003 -.000 holes 2.635" deep in Mild steel. The holes need to have a close to flat bottom. Have you guys used any indexable drills that will hold this tolerance? I have a smaller size .937" that I plan to circular inperpolate to get the size hole I need, but would like to use a 1.00" drill if possible.

Thanks,

Scott

[solgood]

Scott

first thing is index drills wont give you a flat bottom so you will have to use your .937 and finish with an endmill.

second is yes a good index drill will hold +.003-.000

[Fudd]

The bottom does not have to be perfectly flat. Most of the 2 insert drills that I have seen will product flat enough bottom. What drills would you recommend?

Thanks,

Scott

[nervis1]

I doubt you will drill and hold .003 -.000. You will need to drill undesize and ream. Drills are crude hole makers. That being said I have an indexable 1" Mitsubishi drill that is like buttah'.

[solgood]

OK NERVIS1 i do it all day long, never under sized but never over .003 over sized. maybe its the machine(s) you have.

[nervis1]

Maybe so, I'm used to using a 95 Fadal so maybe that is my problem.

[Fudd]

Solgood,
What drill are you using? I have a Sandvik corodrill 880 in .937" That I am planning on using to plunge 1st then interpolate to get to 1.001". By the way I am using a 1990 Fadal 4020.

Thanks,

Scott

[cdlenterprises]

I've always had good luck with Carboloy drills either the SD52 or SD55 series. I wouldn't recommend drilling the holes to size but you may find a metric size that will get you closer to the 1.001 before interpolating it.

[kuss22]

Originally Posted by Fudd Solgood, What drill are you using? I have a Sandvik corodrill 880 in .937" That I am planning on using to plunge 1st then interpolate to get to 1.001". By the way I am using a 1990 Fadal 4020. Thanks, Scott

I have 10 Sandvik Coromant Corodrill 880's with 40 inserts for sale. (All new in original packaging) Make an offer if you’re interested! See Item number: 280160832506 on ebay if you want to place a bid. You can also copy and paste the following link:

http://cgi.ebay.com/10-Sandvik-CoroD...QQcmdZViewItem

Let me know if there is a certain area to post this information. I feel that all the people on this forum will be the most interested in these!

[Fudd]

E-mail sent

Thanks,

scott

[kuss22]

Please feel free to ask questions for I will try my best to get you the answers quickly as possible!

[Metalcutter]

Try a K-tool flat bottom drill. Their website is http://www.ktoolinc.com . I use these all the time. They have a nice flat bottom (except for a tiny tit in the middle). They tend to cut a bit undersize so shimming out the outside insert might be in order. They work better cutting a blind hole.