# Basic questions from a beginner.



## Slowhand1843 (Jul 30, 2015)

I have a few basic questions. When using a tennen and Motrise is the a mathematical equation to determine the size to use, and is there a ratio for the thickness of a Tennon in relation to the length?
When using a dovetail how do you determine the size of the dovetail? Is there a rule as to which part of the dovetail to start with, the male or female? I intend on buying a dovetail jig, any recommendations would be appreciated. I will attempt to cut some by hand just so I know what it's like. At what angle do you cut the dovetail, and with which type of saw?
Are these the only tools needed a saw, a chisel and a hammer or mallet?

I appreciate everyone's help.


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## Mort (Jan 4, 2014)

Slowhand1843 said:


> I have a few basic questions. When using a tennen and Motrise is the a mathematical equation to determine the size to use, and is there a ratio for the thickness of a Tennon in relation to the length?


The tenon is 1/3 the thickness of the wood. As far as the length of it, I'm not sure.



> When using a dovetail how do you determine the size of the dovetail?


There are no hard and fast rules. Some guys like them evenly spaced, some like really thin tails.



> Is there a rule as to which part of the dovetail to start with, the male or female?


Well, there isn't really a male or female, but there are pins and tails. Start with the pins, they'll determine the size of the tails. There are several great YouTube videos on cutting dovetails by hand. I haven't been brave enough to try it yet, but they make it look pretty easy.



> I intend on buying a dovetail jig, any recommendations would be appreciated.


Al B Thayer, a member here, has plans for sale to build your own. I have them, they look very easy, although I haven't yet had any extra time to build the jig.



> I will attempt to cut some by hand just so I know what it's like. At what angle do you cut the dovetail, and with which type of saw?


As far as I remember, 14 degrees. Either a dovetail saw or a back saw, something rigid. 



> Are these the only tools needed a saw, a chisel and a hammer or mallet?


A bevel gauge is needed, and a marking gauge is also handy.


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## NickB (Sep 24, 2013)

Mort said:


> The tenon is 1/3 the thickness of the wood. As far as the length of it, I'm not sure.


Some use 1/3. Some use 1/2 or somewhere in between. You'd probably never notice the difference either way because an M&T is one hell of a strong joint...

From Woodcraft:








Mortise and Tenon Dimensions


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## 4DThinker (Mar 13, 2013)

Generally a tenon should be longer than it is wide. Only cut tenons in end grain not side grain. If the board is wide split the tenons into two (or more if wider). Otherwise the long single mortise weakens the joint.


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