# PCB drill bits?

#### Mathematics!

Joined Jul 21, 2008
1,022
Quote:
Most PCB applications you will need PCB Milling Drill Bits.... I do not know where you are located since you do not show your location, but if you are anywhere near a Harbor Freight get these bits that I mentioned in the other post....

#### BMorse

Joined Sep 26, 2009
2,675
In years past, those $20 PCB drill kits are made from resharpened drills. You have no choice over the sizes. And they're solid carbide and very easy to break. To use them well, you need a small, sensitive, high speed drill press. those only cost$4.99 for 2 10 packs

#### Mathematics!

Joined Jul 21, 2008
1,022
Ok , I am probably going to get the set

Originally Posted by rhythmtech
http://www.harborfreight.com/cpi/cta...emnumber=44924

Looks like this is the set he is talking about.

But I am also curious of what PCB drill bits are used the most, may want to get a couple extra of a particular size????

And also just making sure the drill bits will work in my drill I have a dremel model 300 will these drill bits fit into my drill?

Quote ?????????
To use them well, you need a small, sensitive, high speed drill press?????????

This is the links to the drill and drill press I bought and have. Hopefully these drill bits can be used with this without any addition stuff.
http://www.dremel.com/en-us/Tools/Pages/ToolDetail.aspx?pid=300+Series

http://www.dremel.com/en-us/AttachmentsAndAccessories/Pages/AttachmentsDetail.aspx?pid=220-01

Last edited:

#### SgtWookie

Joined Jul 17, 2007
22,201
.032" is pretty common, and pretty common to break because it's so small.

#### Mathematics!

Joined Jul 21, 2008
1,022
Ok I modified what I said in the last post I did.

I want to make sure these drill bits will fit my drill and work properly with my drill press ,...etc

check my last post for details on my drill / drill press ,....i.e links to the specification page etc

If these are going to work well with my setup (without any additional things needed) then I am all set for now

Thanks again
Does look like a great price.

#### PackratKing

Joined Jul 13, 2008
843
These drills were enormously popular at National Camera [ repair school ] circa 1976 - 77

#### Bernard

Joined Aug 7, 2008
5,227
Just checked a PC bd for hole sizes, # 70- .028, #67- .032, # 61- .039; some common lead sizes: 1/8W res. .o17, 1/4W .o23-.025, 1/2W .033, 1N914 .020, IC pin .018, .1 cap .032, & if using fluted eyelets ,around .036

#### Mathematics!

Joined Jul 21, 2008
1,022
Yes, but I am curious if these drill bits will work with my dremel drill press and dremel drill model 300.

If so I am all set and ready to order them just want to be sure before I ordered them if they will work great with my drill ...etc ?

Thanks
And just curious what drill bits sizes do you use the most for PCB etching.
And if you can buy a certain size seperately from all the rest. Maybe say a pack of 5 .032" bits ?

#### BMorse

Joined Sep 26, 2009
2,675
these bits have a .125" (1/8") shaft so they will work with any dremmel.... Since these are assorted sizes, you might want to pick up 2 packs (that's 40 bits all together), I usually like to visit the store myself and take a look at them, just to make sure I do not get too many of the same sizes (they are color coded for the different sizes).

They will work with what setup you have, you do not need a high speed drill press for it, I use them with my dremmel and I do not have any problems with the speed. I do break a lot of them when trying to drill holes by hand.... good thing they are cheap!

Save the broken ones when you do break them, they come in handy for hand etching PCB's by hand with the dremmel, the little sharp edges work really well in tight spaces.

#### SgtWookie

Joined Jul 17, 2007
22,201
You will go through a lot of the #66 or #67 bits (around .032"). I wouldn't try drilling anything smaller than that by hand. This is the most common size that you will need.

#### gerty

Joined Aug 30, 2007
1,248
Dremmel has a chuck that accepts the 1/8" shank, they also have adaptor bushings for various other sizes. What I prefer is the drill chuck which accepts any size up to the 1/8", with that there is no need for the different inserts.
Dremmel also make a small drill set that is not carbide, therfore they don't break as easy, or last as long.

#### BMorse

Joined Sep 26, 2009
2,675
Dremmel has a chuck that accepts the 1/8" shank, they also have adaptor bushings for various other sizes. What I prefer is the drill chuck which accepts any size up to the 1/8", with that there is no need for the different inserts.
Dremmel also make a small drill set that is not carbide, therfore they don't break as easy, or last as long.

Those adjustable chucks are not very reliable, everyone I have owned crapped out on me before too long, and the offset on it is not suitable for PCB drilling or milling since it has too much wobble. The snake attachment for the dremmel on the other hand is very stable, which is what I use as the tool holder for my dremmel when milling circuit boards...

As for those dremmel bits.... compare prices to one of those bits to a pack of the refurbished milling bits... They may not break easy, but they still break, but costs more in the long run....

My .02

#### gerty

Joined Aug 30, 2007
1,248
Those adjustable chucks are not very reliable, everyone I have owned crapped out on me before too long, and the offset on it is not suitable for PCB drilling or milling since it has too much wobble
That's odd, I have one at the house and another here at school.
Neither has given me a minutes trouble, maybe I don't use them as often as you do.
As for the bits, yeah I know they don't last as long, just offered them as an alternative to the fragile carbide. We use carbide here at school, and the students learn quickly about how easily they break when you aren't paying attention.

#### SgtWookie

Joined Jul 17, 2007
22,201
A collet-type chuck works the best for those tiny drill bits. 3-jaw Jacob-type chucks just aren't as accurate in their centering.