# how to drill a .750 hole with 1/8" bit?



## flyforever (Jan 4, 2013)

I am currently using a 1/8" x 3" long carbide drill to drill into 3/4" MDF, but the bit screams despite the slow speed and attempts to lubricate it.
Is there a better bit available? Most of the bits I see are no more than 1/2" long in flute length. Or any tricks perhaps? 
thanks
tony


----------



## Stick486 (Jan 4, 2013)

flyforever said:


> I am currently using a 1/8" x 3" long carbide drill to drill into 3/4" MDF, but the bit screams despite the slow speed and attempts to lubricate it.
> Is there a better bit available? Most of the bits I see are no more than 1/2" long in flute length. Or any tricks perhaps?
> thanks
> tony


are yo sure it's the bit screaming in the material and not slipping in the chuck???
whose brand of bit???
stop biting off more than the bit can chew...
short drilling and pull out to clean/clear the cuttings


----------



## fixtureman (Jul 5, 2012)

A screaming bit is a hungry bit bump the speed up a little and see what happens. I listen to the dound and adjust my speed according to that


----------



## Cherryville Chuck (Sep 28, 2010)

The screaming could be the waste not getting cleaned out of the cut and getting burnished, along with the sides of the hole. The resins and the cellulose in the wood are forming plastic against plastic if they get hot enough. Like Stick suggested, if the bit stops drilling back it out and clear the flutes.


----------



## Handy48 (Apr 9, 2015)

The smaller the drill bit the faster the speed and more pecking is required to clear the flutes...


----------



## skiroy56 (Aug 7, 2011)

As Handy48 suggested crank up the RPM and peck drill. Smaller = faster, larger = slower RPM's.


----------



## DesertRatTom (Jul 3, 2012)

First time I've heard the term pecking a bit. Turns out I do it already. It basically means backing a drill out to clear out the hole, then back in to drill a little deeper. You could do this several times if drilling a deep hole. Youtube video of pecking at www.youtube.com/watch?v=s6avL3ZYTIQ. Learned something new, thanks.


----------



## Red Stick (Sep 7, 2011)

Doesn't everybody do that?


----------



## fixtureman (Jul 5, 2012)

Red Stick said:


> Doesn't everybody do that?


We don't at work but we have a Biesse with a drill bank


----------



## subtleaccents (Nov 5, 2011)

The resins in MDF will build up quickly and clog the root of the spiral. Generally this comes from creating too much heat by turning the bit too fast and not feeding quickly enough.
Slow your spindle speed down and see how that works. 
I machine large amounts of 3/4" MDF on my CNC router. Generally I have good success with the slow spiral up cut bits from Amana, Bosch and Onsrud.
Compression bits have a root in the spiral that is not very deep and this causes a higher heat and excessive resin build up. I had to go back to up cut
bits and clean the fuzz from the top edge of the material after cutting.


----------

