# What kind Endmill is this?



## oskar (Aug 8, 2018)

I found in my shop 6 similar endmills in a box which I bought in 2011 and have no idea what they are for. Total length is 1.75”, 1/8” Shank, 1/8” OD and 2 are 2 flute, 2 single flute and 2 V shape ends.

What the purpose of the orange sleeve at the end of the shank?

If I will use them to trim aluminum what will be the recommended RPM?


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## 4ssss (Aug 8, 2018)

Looks to be a normal 2 flute long end mill. The sleeve may be to dampen vibration, or it may be just a stop to eyeball depth.


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## Ed ke6bnl (Aug 8, 2018)

I have some of those, I think the sleeve may be for quick ID for size by color


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## BaronJ (Aug 8, 2018)

Hi Guys,

I have some like that, all 1/8" shank, drill sizes from 5mm right down to 0.3 mm,  and also some burrs,  mine are intended to be used in an automatic printed circuit drilling and routing machines.

The colour indicates size and sets the depth in the collet of the machine.  Sometimes there is a number engraved on the collar.  These are often placed in carousels so the machine can select them as required.


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## MAKEITOUTOFWOOD (Aug 10, 2018)

A small one.


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## GrayTech (Aug 10, 2018)

Confirming those collars are used on bits for pcboard routers. Probably not intended for much heavier work. I have quite a few tiny drill bits like that. 

Sent from my H3123 using Tapatalk


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## BaronJ (Aug 11, 2018)

Hi Guys,

The fine carbide ones go down to 0.1 mm, they are good for burner gas jets,  but you need to spin them really fast, around 25 - 35 K rpm.


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## 38super (Aug 12, 2018)

Very brittle.


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## BaronJ (Aug 12, 2018)

Hi 38super,

I agree !  Blow a bit hard on those finer ones and they just snap off.  The other issue is if you catch your hand or finger, the drill embeds its self in your flesh.


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## 38super (Aug 12, 2018)

Ooops.


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## pdentrem (Aug 12, 2018)

We spin 0.012” and the 0.020” at 60K and usually with 10-40 ipm feed depending on what we are doing. They are brittle on side loading but surprising robust at speed. We lose more due to wear and next lost is to the initial plunge.


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## BaronJ (Aug 13, 2018)

Hi Guys,

I once bought a box of 25 sub 1 mm ones on fleabay, they all were reground left hand !  It took me a while to understand why they instantly snapped on touching the workpiece.  They make good dowel pins though.


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## Ken from ontario (Aug 19, 2018)

BaronJ said:


> Hi Guys,
> 
> The fine carbide ones go down to 0.1 mm, they are good for burner gas jets,  but you need to spin them really fast, around 25 - 35 K rpm.


I bought a set of these Tungsten steel carbide (0.3 - 1.2mm) after I broke a few HSS micro bits while drilling .040" holes in my shop made misters but I had no idea they need to spin 25000 K, the only way I could achieve that high of RPM is if I use my woodworking router.
I don't know how many of us here have lathes or mills capable of going the high. at least I didn't pay too much for these bits.


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## BaronJ (Aug 20, 2018)

Hi Ken,

Very few machines will run at those speeds.  Normally you would need a high speed spindle.  Most people would have to make one or buy a specialist unit.  

A very cheap way would be to buy a "Dremel" and mount it in some way so you can take advantage of the speed that it can run at.
I'm sure I've seen a post where a chap made a tool post holder for one, and another who made a bracket so he could use his drill press.
The major problem with these schemes is vibration !  It takes very little to shatter a tiny carbide drill.


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## oskar (Aug 21, 2018)

Thanks to all for the info


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## BaronJ (Aug 22, 2018)

Hi Guys,

If you ever get chance to have a look around a PCB manufacturing plant, do so, the CNC drilling machines have air spindles.  They can drill five boards at once.  The thing that grabbed me was the lack of noise, almost silent. The vent fans were where most of the noise came from.

The plant I saw is no longer there.  I used to get cheap (free) PCB material from them.


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