# Machinist Burrs - What Are They For?



## Morgan RedHawk (Apr 19, 2015)

I recently bought a tooling lot off of fleabay and it included a burr (like a giant dremel bit for my fellow newbs).  I realized that I had not seen one used or really ever heard anyone talk about them before.

What are they for, and how does one use them?
Any information or pics of work done with them would be appreciated!

Here is a pic of some for any other newbs that may not have heard of them:


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## randyc (Apr 19, 2015)

They are used in die grinders to de-burr, chamfer, round-over and other contouring operations that can be done by hand.  They are especially useful on hard materials - sometimes even for some light weld prepping.


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## JimDawson (Apr 19, 2015)

Those are junk, just send them to me for safe disposal 

Seriously, they are normally used in a die grinder or even an electric drill for hand shaping and deburing.  They will cut reasonably hard steel, aluminum and many materials.  It looks like you might have about $100 or so worth of carbide burrs there.  Good find.


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## planeflyer21 (Apr 19, 2015)

In one shop where I worked, we would fight over the flame-shaped burrs.  Ours were typically 1/8" shank and used for deburring.

Takes some practice to become proficient...in each material.  You can scrap a part in the fraction of a second.


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## randyc (Apr 19, 2015)

planeflyer21 said:


> ...Takes some practice to become proficient...in each material.  You can scrap a part in the fraction of a second.



Ain't it the truth !  It's a two-hand operation for me, one hand holding the die grinder body and the other hand as close to the nose as I can safely grip, to help guide the cutter !  As you allude, going from steel to aluminum with a burr can be <ahem> an "interesting" experience.

("Interesting" used in the context as the ancient Chinese curse:  "May you live in interesting times".)


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## great white (Apr 19, 2015)

I use them (along with stones) to port cast iron and aluminum (no stones on Al) engine cylinder heads.


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## Morgan RedHawk (Apr 20, 2015)

Thanks, yall!  

Unfortunately, those burrs in the picture are not mine, it was just an internet picture I found for reference.  I only got one cylindrical burr with the tooling, but it feels nice and sharp.  

Any special precautions I should know about?


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## JimDawson (Apr 20, 2015)

Morgan RedHawk said:


> Any special precautions I should know about?




Just don't let it get away from you, they tend to grab.  A little practice will give you a more steady hand when using this type of cutter.  And they generate nasty little slivers.  Eye protection is an absolute must.


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## OldMachinist (Apr 20, 2015)

Like Jim said they make the nastiest little slivers that go everywhere. Try to use them in a spot that's easy to vacuum after your done or you'll be picking them out of your hands for months.
If you use them on aluminum use some type of lube or the teeth will get clogged.


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## davidh (Apr 20, 2015)

and gloves, don't forget the gloves.  the double-cut burrs pictured on the left are less burr creating than the single cut ones on the right.  often the die grinder you use has a front exhaust and then you are literally blowing these little nasty in places you will find at another time, when you do not wear gloves like grabbing a wrench that has a bit of oil on the handle. . .  it will also have a family of ittybitty slivers just waiting for your hand.


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## OldMachinist (Apr 20, 2015)

JimDawson said:


> It looks like you might have about $100 or so worth of carbide burrs there.



So Jim I wonder how much these are worth.



Picked them up at a McDonnell Douglas(now Boeing) auction many years ago for $25 when no one else bid on them. Those are just the new ones I have a drawer full of slightly used in my tool box too.


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## JimDawson (Apr 20, 2015)

Current Enco prices run between $6 and $40 each depending on size, so you have quite a bit a value there.


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## atlas ten (Apr 20, 2015)

I uaed same style in at machine shop I work in. Was using them on crome stators in down hole drilling tools. The machinist that was teaching me the trade told me that the second cut are for hard materials and the single (continuous cutting edge) are for aluminum. They remove material fast when they are new. 
Jack


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## Dave Smith (Apr 20, 2015)

very good find Don--if I had been at the auction you may not have gotten them ---I use them all the time---Dave


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## Marvelicious (Apr 21, 2015)

They actually make burrs specifically for aluminum which are much coarser than those.  They look like something you would use on wood (probably would work for that as well...).  Burr bits are the most handy but infuriating tools available: they make the most evil metal shavings imaginable!


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## Bob Korves (Apr 21, 2015)

I have a few carbide single cut burrs with 3/8" shanks.  Any idea what kind of tool drives them?  Whatever tool it is, it might be too much for me to hang on to.  I have thought about trying them on the mill, but I don't know what for...


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## dlane (Apr 27, 2015)

Hi all , I picked these diamond burs a while back the price was rite $10.00 I'm guessing they would work on carbide ,any  thoughts, they have 1/4" shanks
Dreeick


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## JimDawson (Apr 27, 2015)

They would work very well on carbide.


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## Ripthorn (Apr 30, 2015)

I recently used some of the cheapo HF diamond coated burrs in dremel to ground out part of a broken tap.  I was able to drill relieve holes to either side, then get the little burr in there and get rid of the material.  Worked much better than I expected, considering they were part of a super cheap accessories package. 

I have used the carbide ones in shaping the escapements for shoulder planes in mild steel.  They are amazing for free hand shaping of complex shapes.  Just beware them slivers!


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## kingmt01 (May 6, 2015)

I haven't bought any in years but I paid about 50 cent a piece for 3/16" shaft I think. They are handy when you need them but I don't use them often. My sugestion is dont let it dig in & push it easy towards the meteral.


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