# Lock Miter Bit



## pusserboy (Mar 4, 2018)

If you have a lock miter bit for 3/4 " stock can you use it for 1/2 " stock or do I have to buy a new bit.Stuart


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## Stick486 (Jan 4, 2013)

if the bit is rated for that thickness and it'll take a little more finessing bit sure .. go for it...
cheat...
use a rebated rabbet..

...


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## Semipro (Mar 22, 2013)

They sale a bit for 1/2” 3/4” and 1” material


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## Stick486 (Jan 4, 2013)

Semipro said:


> They sale a bit for 1/2” 3/4” and 1” material


he has a bit for ¾ material


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## harrysin (Jan 15, 2007)

Yes, you can use the 3/4" bit for 1/2" stock. This is a wonderful joint and once the set-up has been mastered it's hardly more difficult to make than a simple mitre.
Once the set-up is spot on for a particular thickness wood, make and keep a test piece for easy set-up when using that thickness wood in the future.


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## pusserboy (Mar 4, 2018)

Thank you all for the replies that will save me some money thats great!
Stuart


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## Cherryville Chuck (Sep 28, 2010)

The set up will be different for every thickness you use it for. There is a point on the profile that has to be centred on the thickness of the boards.


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## DesertRatTom (Jul 3, 2012)

Check out the Marc Sommerfeld Easy Set jig. It's made for his brand bits (yellow version) and Freud (red version). The jig has 6 points, each a jig for a different common bit, including the locking miter. It also has a dial to set the thickness of the wood. It costs a bit less than $30 and is very helpful and accurate for setup. Here's a video on how to use it. 



 I've tried other jigs, but this one is the best so far. You will need to measure the thickness pretty accurately, I use a dial gauge caliper for that.


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## Gene Howe (Jul 10, 2007)

Tom, his disclaimer states the yellow jig will only work with Sommerfeld bits. Do you use it with other lock miter bits?


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## Herb Stoops (Aug 28, 2012)

I have the Red ones from Infinity and use with Infinity bits.

Herb


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## ScottyDBQ (Jul 5, 2008)

Tom, Thanks for the info on the set up jig.


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## Herb Stoops (Aug 28, 2012)

Gene Howe said:


> Tom, his disclaimer states the yellow jig will only work with Sommerfeld bits. Do you use it with other lock miter bits?


That is a good question, I have often wondered if the lock miter profile was a standard profile.


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## DesertRatTom (Jul 3, 2012)

Gene Howe said:


> Tom, his disclaimer states the yellow jig will only work with Sommerfeld bits. Do you use it with other lock miter bits?


I normally use it with his brand bits, but nearly all my other bits are Freud. 

I've come to the point where I tend to buy Sommerfeld bits when I need something. The carbide is nice and thick. He ought to give me a discount, but no such luck. I just like the quality.

I've tried a couple of other brand jigs, but they were all a little flakey. The difficulty is with the thickness. But it is possible to set up by placing the center point at the middle of the workpiece. Even then, this bit is very fussy.


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## CharleyL (Feb 28, 2009)

The Lock Miter Master set-up jigs sold by Infinity Tool work very well and make setting up both the bit height and fence position very easy for just about any lock miter bit or size. It attaches to the bit cutting face with included rare earth magnets. Once on the bit, there are set up lines on the jig that you adjust until the line is centered on the board that you intend to cut. Finding the exact center of each board thickness is harder than using the jig, but can be done using several easy techniques. I use the Rockler center marking tool Rockler Center/Offset Marking Tool | Rockler Woodworking and Hardware
You could also place a ruler scale diagonal across the board edge of a 1/4 - 1" thick board with the 1" mark on one edge and the 4" mark on the other board edge. The board center in this case will be at the 1.5" position of the scale. 

Charley


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## Stick486 (Jan 4, 2013)

Herb Stoops said:


> That is a good question, I have often wondered if the lock miter profile was a standard profile.


seems to be a fuzz different manufacturer to manufacturer..


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## Clt1bkc (Feb 19, 2015)

http://go.rockler.com/tech/Rockler-Drawer-Lock-Router-Bit-Instructions.pdf


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## DesertRatTom (Jul 3, 2012)

Gene Howe said:


> Tom, his disclaimer states the yellow jig will only work with Sommerfeld bits. Do you use it with other lock miter bits?


I have two of these bits, but only use the Sommerfeld version with the yellow EasySet jig. You can purchase the other one for Freud. Someone is using the red bit for another brand (above). The key is the ability to set the board thickness precisely, which makes both sides of the joint line up. I think the other brand was Infinity, but double check above. 

I also have a tiny jig that is universal, but I never used it, it was so tiny I didn't trust it. Can't remember the maker. 

One thing about using the bit is that you want to set it and not change it during the task. To do this it really helps to put a half inch grommet in the collet to bottom out the bit against the grommet. Without the grommet, you could find a tiny amount of creep that would mess up your joint. 

I don't know exactly why you can't just line up any such bit with the Sommerfeld jigs since they are all basically 45 degrees with a small jog in the middle. Perhaps there is a difference in the size of the jog? This is not a terribly expensive bit, so I'd consider ordering a Freud Lock Miter bit and the Red jig.


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## Hypnotoad (Apr 17, 2018)

I got good information on setting up a lock mitre bit from Youtube, using that method I got it right the first time I tried the bit. So make a horizontal test cut with two pieces with the bit about the right height, then if the flipped over piece is higher than the other piece then you need to raise the bit and vice verse.

Only then worry about the depth of the fence and doing the vertical cut piece. Setup jigs only work on material the same thickness their designed for, dressed timber varies more than you think.


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## Gene Howe (Jul 10, 2007)

Hypnotoad, That's the method I use. For non standard thicknesses, it's a lot easier than other methods.


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## pusserboy (Mar 4, 2018)

Thanks everyone I think I'll buy the one for each thickness of the stock and make life easy.
Stuart


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