# slot drills v end mills



## alanfisher (Oct 2, 2014)

Hi all, what are the basic differences in slot drills and end mills?

I assume end mills would mill a slot? how much cut to make each pass?
if an end mill will go all the way through? would the end mill not be suffice?

Oh! I am confused.


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## OldMachinist (Oct 2, 2014)

It's regional terminology thing. What you call a slot drill in the UK we in north America call a end mill also. Slot drills in the UK are center cutting mills and end mills are non center cutting. We call them all end mills.


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## Bill Gruby (Oct 2, 2014)

Ditto on what Don said.

 "Billy G"


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## hermetic (Oct 2, 2014)

Just to expand on that a bit, end mills will only cut a slot as deep as the projection depth of the lower teeth, there is no cutting edge to the centre so they will not plunge or cut a slot, only a slot drill will do that,hence the name.a slot drill usually has one long and one short cutting edge, the long one goes all the way to the centre. Some "throw away" end mills will also slot cut as they have (usually) three flutes and cutting edges which go to the centre. 
Phil


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## alanfisher (Oct 3, 2014)

Many thanks
That clears it up for me.

I love this forum.


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## Frank Ford (Oct 4, 2014)

When I hear "slot drill" I think of end mill drill, like this one:



It's the tool for drilling through and slotting without changing bits.

I see the flat end mill that cuts downward listed as "center cutting end mill."  It can drill its own hole, but somewhat reluctantly by comparison.


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## lnr729 (Oct 4, 2014)

OldMachinist said:


> It's regional terminology thing. What you call a slot drill in the UK we in north America call a end mill also. Slot drills in the UK are center cutting mills and end mills are non center cutting. We call them all end mills.



In the common vernacular you are correct however the machinery's hand book does make the distinction between slot drills and end mills as do most industrial tooling catalogs. If I go to the local industrial supply and ask for a slot drill I get a quizzled look but a 2 flute end mill gets what I am after


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## hermetic (Oct 4, 2014)

An end mill drill, now that sounds interesting, I wonder if we have them in the UK/ I will have a look.
Phil


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