Miniature drill bits

[moe1942]

Looks like these might be useful in clock work. Look pretty rigid.


http://drillbitcity.com/

 

[bangster]

Re-sharpened carbide bits can indeed be useful, especially when re-pivoting. But be warned: they are not only very hard, but very brittle. Break one off inside the end of an arbor, and you have a Situation. They need to be handled with a light touch to avoid breakage.

 

[moe1942]

Re-sharpened carbide bits can indeed be useful, especially when re-pivoting. But be warned: they are not only very hard, but very brittle. Break one off inside the end of an arbor, and you have a Situation. They need to be handled with a light touch to avoid breakage.

These are definitely not for pivot work but the uninitiated need to know that. I only use pivot drills for pivot work.

I was thinking they would be good for general work. I'm not sure I would even use them to prep for a bushing. I will evaluate their usefulness when I have them in hand. I just posted to let others decide if they have merit.

 

[David S]

Interesting I just got some new (not resharpened) bits that look the same as what your are showing. My first job was to use a 0.9mm bit to drill out the roots of some new teeth I dovetailed into a wheel. I put the wheel with the replaced section in my rotary table and with a light touch was able to drill 4 holes without a center drill. So far so good.

 

[whattime]

Thanks for the info

 

[Thyme]

Looks like these might be useful in clock work. Look pretty rigid.


http://drillbitcity.com/

The older type carbide drills used in dentistry are often useful. They are known as straight handpiece burs and have the same same shank diameter as Dremel tool bits.

I have some available. If anyone is interested or wants more information, please contact me by private message.

 

[moe1942]

The older type carbide drills used in dentistry are often useful. They are known as straight handpiece burs and have the same same shank diameter as Dremel tool bits.

I have some available. If anyone is interested or wants more information, please contact me by private message.

I get some burrs everytime I visit my dentist.

 

[dAz57]

I use them for pivot work, I had to repivot an escape wheel from a platform, removed the escape wheel, drilled out a 0.8mm hole in the hard 2mm arbour, then drove a plug into the hole, the plug also had to be the shoulder the escape wheel fits back onto, then turned and polished the 0.15mm pivot.

these drills are great in that don't have to soften the arbour first, I find slow speed works best, these drills are very sharp, just make sure the centres are true and no drill wobble, otherwise they will break, I even used one in a hand drill to drill into stainless steel (very carefully) the other day.

these drills are used in the electronics industry for drilling holes in circuit boards, circuit boards will blunt a normal drill in a very short time, I get mine off ebay where they are quite cheap compared to what they cost years ago

 

[Ralph B]

As pointed out they are very brittle and need a lot of care in use.
Mainly because they are so long. If they re-sharpened them to about half the length they would be stronger and more useful.

Ralph B.

 

[leeinv66]

They need to be handled with a light touch to avoid breakage.

That's good advise when using any small diameter bits Bangster

 

[AJSBSA]

I use them for pivot work they cut French arbors like butter, however they need to be centred first and will snap like carrots if mis-treated so you need a good lathe and a light touch

 

[moe1942]

I prefer pivot drills cause they are carbon steel and if I snap one off I know I won't get punished getting it out. Carbide and HSS drills will punish you to no end if they break.. If you want to know how much just ask me...

 

[Thyme]

As pointed out they are very brittle and need a lot of care in use.
Mainly because they are so long. If they re-sharpened them to about half the length they would be stronger and more useful.

Ralph B.

When you mention length, do you mean the length of the bur (the cutting part) itself? Dental burs are very short. For illustrations and descriptions of them click here.

 

[moe1942]

Depends on the type hand piece they fit. I have gotten long and short. The short ones have a notched end for locking in and all my long ones are smooth shaft for friction grip. For what I've used them for neither has an advantage over the other.

And the price is right....Free..

 

[Thyme]

Depends on the type hand piece they fit. I have gotten long and short. The short ones have a notched end for locking in and all my long ones are smooth shaft for friction grip. For what I've used them for neither has an advantage over the other.

And the price is right....Free..

The long straight burs are used in what are today called low speed handpieces. ('Low speed' is 20-50,000 RPM, as opposed to high speed handpieces that turn at 300,000 RPM and are water cooled.) Straight burs used to be used in old fashioned dental belt driven handpieces, and are still used on dental lab engines. That's the same type as is used in a Dremel tool. The other type of latch type bur (short, with a notched end) fits right angle (RA) contrangles. A contrangle is a small attachment (that utilizes a shaft and transmission gears) that couples to the end of a straight handpiece allowing it to be used in confined areas at a right angle. When the dentist applies toothpaste to polish your teeth at the end of a professional cleaning, a contrangle that is rubber tipped and made of plastic is used for that. Those are single use and disposable. But the contrangles used to hold a cutting bur are all metal.

I agree - nothing beats "free".

 

[Charles E. Davis]

I use the very small round burs with the long straight handles as miniature center drills. They act as a milling cutter and will go to the correct center on their own. For very small drills they provide a very adequate center for drilling.