# Router Bit Clearance



## tauras (Sep 20, 2008)

Why the minimum clearance spec for some router bits? 

Some of the raised panel door bits have a minimum clearance spec. for a router plate opening of at least 3 5/8”. My Pinnacle Aluminum Router plate has an opening of 3 9/16”. I noticed Freud has cautioned users against using aluminum router plates with 3-5/8" maximum openings”

Why is this? Is it an interference issue? Might the bit strike the plate? Or is it the wood cuttings needs somewhere to go.


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## bobj3 (Jan 17, 2006)

Hi tauras

" Might the bit strike the plate? " you got it ,right on

This is when you need the TP roll hanging on the side of the router table 

This is one of the times you may want to use
Vertical Raised Panel Router Bits
http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/raised_panel_router_bits2.html
Plus they are safer to use than the BIG bits...
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tauras said:


> Why the minimum clearance spec for some router bits?
> 
> Some of the raised panel door bits have a minimum clearance spec. for a router plate opening of at least 3 5/8”. My Pinnacle Aluminum Router plate has an opening of 3 9/16”. I noticed Freud has cautioned users against using aluminum router plates with 3-5/8" maximum openings”
> 
> Why is this? Is it an interference issue? Might the bit strike the plate? Or is it the wood cuttings needs somewhere to go.


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## tauras (Sep 20, 2008)

Hi bobj3,

So what is the minimum clearance?

A 3-1/2" diameter bit would only give a 1/32 clearance on my Pinnacle aluminum router plate. Not enough, correct?

Is 1/8 enough or wider?


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## Charles M (Apr 10, 2006)

tauras said:


> I noticed Freud has cautioned users against using aluminum router plates with 3-5/8" maximum openings”



I think you mean "against using with router table plates with less than 3-5/8" opening". And the answer is that you do need at least 1/16" clearance all around for the bit.

Welcome to the group!


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## bobj3 (Jan 17, 2006)

Hi tauras

1/8" is not enough,,, but that's just my cents,,, the router bits are made very true but the plates are not, they can shift or move just a little bit.

If you want to use the bit you have open the hole so it's bigger it's not a big job...  I like to see 1/4" on both sides of the bit, the panel bits do pull of tons of chips off and they got to go somewhere, it's true most will go out the back end to the Vac.tube but not all of them..

Play it safe after all it's just a wooden door panel you're working on..

Here's a* small trick* I use when I use the BIG bits..

Get some 3/4" thick MDF/Plywood and cut a 4 1/2" hole in the center then clamp it to the router table top.
You can slide it right up to the fence if you want, (if you cut some of the hole off ) the only thing that needs to be up and out are the cutters on the bit.

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tauras said:


> Hi bobj3,
> 
> So what is the minimum clearance?
> 
> ...


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