# Standard Rabbet Depth



## Tom5151 (Nov 21, 2008)

What is the rule of thumb for rabbet depth? I have read that it should be about half the depth of the material being "rabbeted". Is that accurate?

I am making a cab out of 3/4 stock and am planning on 3/8 depth.

Thanks


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## Rob (Oct 31, 2006)

I think the depth depends on what you are putting in the rabbet. If I'm making a frame for a picture, the rabbet will be equal the thickness of the glass, backing, etc. If I'm making a rabbet for a cabinet back, the depth will be whatever thickness the material used for the back is.


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## Tom5151 (Nov 21, 2008)

Maybe i am using the wrong term. Maybe i should be asking about rabbet width?

I basically want to know how deep i can cut into the material being rabbeted before i start compromising strength. I have read no more than half the thickness of the material being rabbetted

I am buliding a box shelf. It will have a top and bottom member both at 48 inches long and 12 inches deep. It will have two sides at 12 inches high and 12 inches deep. . The top and bottom edges of the sides of the shelf will be rabbeted to accept the top and bottom members of the unit. All material is 3/4. I want to know how far I should cut into the thickness of the side members of the unit. From what I have read, I am thinking 3/8 would be sufficeint.


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## Rob (Oct 31, 2006)

I think 1/2 the thickness is safe. When I want to make sure I have plenty of room to set brads, I give myself more width. On some cases I'm currently making from 3/4" ply, the rabbets are 1/2" wide. This gives me plenty of glue area plus room to make sure the brads are not shooting out either side. I don't feel I've compromised strength with leaving just 1/4".


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## Tom5151 (Nov 21, 2008)

Rob said:


> I think 1/2 the thickness is safe. When I want to make sure I have plenty of room to set brads, I give myself more width. On some cases I'm currently making from 3/4" ply, the rabbets are 1/2" wide. This gives me plenty of glue area plus room to make sure the brads are not shooting out either side. I don't feel I've compromised strength with leaving just 1/4".


perfect....thank you for taking the time to reply....this will help me alot.

Tom


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## woodnthings (Jan 24, 2009)

Quote:

Maybe i am using the wrong term. Maybe i should be asking about rabbet *width?*

I basically want to know how *deep* i can cut into the material being rabbeted before i start compromising strength. I have read no more than half the *thickness* of the material being rabbetted"

Hey tom, you lost me when you switched to "width"! The depth of the rabbet, 1/2 the support material thickness is OK, but I usually go a little less than 1/2 the thickness. For example, with 3/4" stock I'll make my rabbets and dadoes 5/16" deep. That leaves plenty of structure and plenty of support for a shelf or divider. Sometimes it depends on how much of the rabbet will show as from the side or the top. In that case you'll want to minimize it and go more than 1/2 thickness.That's my opinion, :smile: bill


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## Tom5151 (Nov 21, 2008)

thank you guys....i appreciate the help........that is exactly what i needed to know........


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## cabinetman (Jul 5, 2007)

I don't know of any "standard" for rabbet depth. There are a lot of "depends on". For starters, so I'm using terminology that's agreeable with everybody else, I'll call "rabbet depth" the depth that is plowed into stock, like the depth of a dado.

I'll call the other dimension the "step", which refers to the width of the rabbet that stops at the "shoulder". I'm thinking the first point in talking about "depth" would depend on the thickness of the stock used. If it's plywood, and it's supposed to be 3/4", multiple sheets may be of different thicknesses, so you should check all the stock first.

The hardwood plywoods I usually buy are 3/4" with a .062 veneer face. The depth of my rabbets and dadoes are 1/4". That way what is left is 1/2", and measurements in the fabrication are easier to figure to add up when knowing what is left. I use the same depths so when I dado a floor of a cabinet it is the same depth as the rabbet is for the back. 

The step would be what you plan for the rabbet. If you rabbet the carcass 1/4" deep, and you're using 1/4" plywood for the back, and you want a 1/2" scribe, your step would be 3/4". Not to throw a curve ball here, but the plywoods you might buy are likely thinner than those even dimensions, and are listed in milimeters. So, your depth of rabbet may be less to give a full 1/2" (of course that depends on the thickness of the stock you're rabbeting).

When using melamine I rabbet/dado very shallow, like 1/8" or less just to get a glue joint.


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## Tom5151 (Nov 21, 2008)

Thanks again guys.........this really is very helpful....

Yeah by standard I was just meaning kind of a rule of thumb. I know there is no one standard for every application. I was more wanting to know generally how deep a rabbet can be made before compromising strength.

Thanks again.


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## Jordy3738 (Jan 12, 2009)

I'd go for the 1/2" dimension. We used to fabricate production cabinetry using 5/8" thick material and the rabbits were always 3/8" deep. It gives enough room to shoot a staple through the top of a rail if you need to.


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