Mini Carbide Drill Bits

[bluestringer]

Nice set of mini carbide bits picked up at Harbor Freight. One eighth inch shaft fits my Dremel Mini Mite perfectly. 

[peteski]

If you use them in a handheld power tool be ready for them to snap. Especially the smaller diameter ones.  They are supper sharp and pleasure to use, but Tungsten Carbide is very hard, and very brittle.  I own a large selection, and whenever I can, I buy the smaller diameter bits by the box of 50.  That way I have lots of spares.  As you can see, these bits are so good that I'm addicted to using them.

 

Probably about 10 years ago, there was a seller on eBay selling them really cheap in boxes of 50.. Some resharpened, some used (with plenty of life still left).  That is when I accumulated most of my stash.

Edited May 5, 2022 by peteski

[NOBLNG]

X2…they are extremely sharp and extremely brittle.?

Edited May 6, 2022 by NOBLNG

[bluestringer]

Thanks guys. Guess that's why they give you 2 of each size. I did notice they are really sharp. I'll only use them for drilling holes for plug wire and such, no heavy work, but if I break one I'll check ebay for replacements. 

[Oliver77]

This is the type of drills used to make holes in circuit boards. The boards are commonly made of fiberglass reinforced epoxy, which is extremely abrasive. The precision drills turn at way high rpm (10000 or more) and move straight down and up, the drills are strong in that direction, but slight side pressure can snap them. (source: I was a circuit board designer in real life)

When (not if!) you break one, you will be glad you have eye protection on.

Regards,

Jeff Oliver

[Chariots of Fire]

Pete is right.  They will snap in a pin vise if any kind of sideways pressure is put in them.  This is especially true if the hole you are drilling is in thick material.  That having been said, I don't know what I would do without them and I use them in a pin vise all the time.  Best thing since sliced bread in my opinion.

[El Roberto]

Here's another source, been buying micro bits from them for quite a while.   drillbitsunlimited.com

[sbk]

Those are the best, & use nothing else for small diameter drilling.

[TarheelRick]

Went to local HF looked for them in the drill bit section, no luck.  Associate offered to help me, couldn't find them so looked up on computer, still no luck.  Anyway, I browsed the store to see if there was anything else I "really needed".  Just happened to stumble across a couple sets hanging on the rack with Dremel bits; both are mine now.  Looking forward to using them.

[Chariots of Fire]

On 5/10/2022 at 2:03 PM, TarheelRick said:

Went to local HF looked for them in the drill bit section, no luck.  Associate offered to help me, couldn't find them so looked up on computer, still no luck.  Anyway, I browsed the store to see if there was anything else I "really needed".  Just happened to stumble across a couple sets hanging on the rack with Dremel bits; both are mine now.  Looking forward to using them.

Try Drill Bits Unlimited on line.  All kinds available at reasonable prices.

[Bugatti Fan]

Oliver has described these bits in detail as they are designed to drill printed circuit boards on a CNC drilling machine that works at high revs.

I amassed a number of them when in the past I worked at a PCB manufacturer.

Very brittle and when subjected to side pressure very easy to break.

[Straightliner59]

You can find boxes of 50 resharps for about $25, shipped. I absolutely love them, in the lathe, drill press and mill! For me, when I am drilling with them, by hand, I just use the bit, itself. It's kind of like choking-up, on a bat, to hit for contact!?

[Bugatti Fan]

Daniel, please explain what you.mean about using the bit itself. The shanks are generally much bigger than the bit diameter, so not sure how you could do that.

Also you said about using them in a mill. OK for vertical pressure like using a drill press but sideways movement would cause breakage on small diameter bits. Are you referring to bits with a larger diameter where the shank and cutting big size would be the same?

[Straightliner59]

3 hours ago, Bugatti Fan said:

Daniel, please explain what you.mean about using the bit itself. The shanks are generally much bigger than the bit diameter, so not sure how you could do that.

Sorry! I just mean that I hold it by the shank, to hand drill, rather than chucking it in something.?

I only use them for drilling, with the mill. As you know, they'll snap, if you look at them, crooked!

[bluestringer]

Yes, I found that I can just hold it my hand and drill heads for spark wires easily. Doesn't take much pressure because they are so sharp. 

[Chariots of Fire]

I've had them break even in a mill with too much pressure on a small size bit.  Nevertheless working with them in a mill, drill press or in a pin vise is possible if one is careful.  I don't know what I would do without them.  I work with #71 size all the time as it is about the same size as a common pin or #24 gauge wire.

[peteski]

I also often drill (in plastic) by holding the shank in my fingers.  That gives me very good control of the precision drilling process.  The 1/8" shank makes this possible.  I've done this with the drill bit as small as #85.  You do need steady hands (propping them on the workbench helps).

Edited May 14, 2022 by peteski

[Bugatti Fan]

Daniel.   Thanks for the clarification. Interesting to note how you other guys use them as well.

[deuces wild]

It also helps to start the hole with a #000 center drill.... Those come with the .125" shank... Perfect for a pin vice...?

[peteski]

On 5/15/2022 at 4:05 AM, deuces wild said:

It also helps to start the hole with a #000 center drill.... Those come with the .125" shank... Perfect for a pin vice...?

All the 1/8" shank Tungsten Carbide PC Board drill bits are sharpened to a split point which does not wander over the material.  But sure, adding a dimple of a starter wont' do any harm.

https://ireviewtools.com/split-point-drill-bits-vs-standard-bits/

Edited May 18, 2022 by peteski

[Straightliner59]

7 hours ago, peteski said:

All the 1/8" shank Tungsten Carbide PC Board drill bits are sharpened to a split point which does not wonder over the material.  But sure, adding a dimple of a starter wont' do any harm.

https://ireviewtools.com/split-point-drill-bits-vs-standard-bits/

That's what I like best about them! In the lathe, I can bore a .020" hole on a .030" rod. I don't have any center drills that would start a hole, that small in a rod, that small!

[Bugatti Fan]

If you think about it those small tungsten carbide bits are not dissimilar in shape to a centre drill that would be used on a lathe.

The only problem that I have encountered when drilling plastics with small drills of any kind is the heat generated that could bind melted plastic onto the bit. My little lathe does not have a variable speed control unfortunately. Those that have benefit by being able to run the machine at slow speeds, therefore reducing the possibility of melting plastic onto the bit.

[peteski]

That's why we often drill by hand.  Can't get any slower than that.

[Rick L]

On 5/15/2022 at 8:40 PM, peteski said:

All the 1/8" shank Tungsten Carbide PC Board drill bits are sharpened to a split point which does not wonder over the material.  But sure, adding a dimple of a starter wont' do any harm.

https://ireviewtools.com/split-point-drill-bits-vs-standard-bits/

I wonder if it wanders?

[peteski]

6 hours ago, Rick L said:

I wonder if it wanders?

LOL!  Fixed it.

But if you ever wondered if split point drill ever wanders . . . it doesn't. No need to wonder any longer.

Edited May 18, 2022 by peteski