# Mortise question



## Mike B. (Jan 7, 2009)

Gents,

I'm getting ready to try my hand at my first mortise and tenon joint, but have a newbie question. If I use a router to cut the mortise, with a 3/8" bit, wouldn't that leave slightly rounded ends? Cutting the tenon with a table saw wouldn't leave matching rounded ends. Do I need to use a chisel to square up the ends of the mortise?

thanks in advance for any advice.


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## rocklobster (Jun 18, 2008)

You're right, the router bit will leave rounded ends. You could use the chisel to square up the ends of the mortise, or you could use a rasp to round over the edges of the tenon. I think rounding the tenon is the better option myself, but it depends on who you ask.

Rob


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## Domer (Mar 23, 2008)

*Mortise Questin*

If there aren't too many tenons, I round them over with a belt sander.

But really, you can leave them square unless it is subject to a lot of shear stress like on a stool stretcher. There is so much end grain glue surface, that it will be a pretty strong joint.

I saw Norm build an outside front door using loose tenons and he left them square.

Domer


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## Terry McGovern (Feb 5, 2009)

When I did that, I rounded them with a file. Only takes a second. I have since bought a dedicated mortiser, and they're all nice and square now.:clap:


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## Tom5151 (Nov 21, 2008)

I recently cut 16 M&T. I did the mortises with a plunge router (rounded corners) and did the tenons with a dado blade on the TS (square corners). I took a very sharp chisel and beveled the corners of each tenon. I probabaly took me a minute max for each tenon. I didn't round them. Just left the angular bevel created by the chisel and they fit very nicely into the mortise.


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## Mike B. (Jan 7, 2009)

Thanks folks. I think I'll try rounding the tenons just for the practice. I'm making a small stand to put my new 42" plasma HD tv on (and my audio reciever will go under the stand), so I'm taking my time and trying to anticipate things. I do plan on making some kindling first, though <G>. I'm using some oak boards I had left over from a room overhaul, where I did some mission style wainscoting, which is where I caught the woodworking bug (biscuted-jointed the styles to the rails, and lap-jointed (with dowels) the rail sections and window frames).

Wish me luck!


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## Tony B (Jul 30, 2008)

*Mike, you dont need luck.*

Just take your time.
If you use a file or rasp to round over the tenons, be very careful that the file/rasp doesnt cut into the outside portion of the shoulder. 

Have fun ....and RELAX and enjoy.


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## johnv51 (Oct 27, 2008)

The last time I made tennons for a router created mortise I just used a utility knife on the corners. I made a cut at the shoulder first then trim off the corner of the tennon.


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## Tom5151 (Nov 21, 2008)

Tony B said:


> Just take your time.
> If you use a file or rasp to round over the tenons, be very careful that the file/rasp doesnt cut into the outside portion of the shoulder.
> 
> Have fun ....and RELAX and enjoy.


totally agree with this advice....when using a rasp or file to round over your tenon corners it is very easy to knick up the shoulders. If you are careful enough to not do that then you are almost surely going to have some material left where the tenon meets the shoulder that you are still going to need to remove. 

The knife or chisel method allows you to start at the end of the tenon and carefully and steadily work back to the shoulder and remove only what you need to remove. You can still knick up the shoulder that way too I suppose but I found I had more control that way. 

Whatever method you use just take your time and have fun.


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## Terry McGovern (Feb 5, 2009)

I didn't use a rasp; too easy to tear chunks off the tenon. I would use a file with a square edge and go slowly at the shoulder, keeping the file square to the shoulder. If necessary, a little touch up with a suitable woodcarving tool makes short work of anything that might be left behind.


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