# proper straight bit size for dadoing



## coupe (Mar 5, 2009)

what size straight bit do you guys normally use for dadoing melamine? 1/2,and 3/4. I no it sounds dumb but I am told melamine is actually .53 in thickness but sold as 1/2. That fractions to 17/32 which i do not find in most of the bit selections of various companys. I have seen alot of 19/32 bits out their. Just asking or maybe their is a thread you can direct me to. Thanks


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## dovetail_65 (Jan 22, 2008)

Well I really never use the same size bit as the dado I need.

Just make the gap you route the correct width and you can even use a 1/4" bit to make the correct size dado.

In other threads there are many examples of this. The simplest is just to clamp a piece of ply. Then clamp another piece of ply 17/32" away from the first and route out the gap between the two pieces of ply.


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## Gene Howe (Jul 10, 2007)

Another way is to slide a piece of your stock between the guides that Nick suggested, snugging up one guide to the stock. That way you have the exact dado width you need, without measuring. I use a pattern bit for this process.


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## Ralph Barker (Dec 15, 2008)

Taking a step back, there are two basic strategies with under- or over-sized materials:

1. make the dado the exact size of the material, using multiple passes with a smaller bit, or

2. make the dado the next "standard" size smaller, and cut a rabbet on the piece to be inserted, so it fits.

There are arguments for both under different circumstances.

For under-sized plywood, most of the bit manufacturers have "plywood bits" that correspond to the nominal thicknesses, such as:

http://eagleamerica.com/3-piece-plywood-dado-sets/p/100-0242/

In practice, however, variations in thickness are often found on individual sheets.


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## bobj3 (Jan 17, 2006)

Hi Ralph

Just one more place to get a set for 14.oo bucks ..

http://grizzly.com/products/Straight-Plywood-3-pc-Set-1-2-/H5559

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