45 Degree Locking Miter Router Bits

  • Advertise with us

« back to Joinery forum

Forum topic by gauntlet21 posted 01-05-2019 09:48 PM 425 views 0 times favorited 4 replies Add to Favorites Watch
View gauntlet21's profile


69 posts in 573 days

01-05-2019 09:48 PM

Topic tags/keywords: 45 degree locking miter router bit joinery

I’ve never used one of these 45 degree locking miter router bits but they seem like a nice idea for alignment and stability purposes. I’m interested in trying them out on some picture frames, small boxes, drawers, etc. The majority of my stock will be in the range of 1/2”-3/4” but I’m not opposed t ok going larger eventually. There seem to be 2 sizes available from each manufacturer, Eagle America, Whiteside, Infinity Tools, etc. They make a smaller model for about $70 that can handle the 1/2-3/4” stock and then a massive one that can do 1/2” to 1-1/8” or even 1-1/4” for about $100-$130.

If you are going to be using the thinner stock (1/2” to 3/4”) is there an advantage that I cannot appreciate by owning the smaller version? Is the setup more difficult on thinner stock with the larger bit or why, would Eagle America offer a 3 piece 4t degree locking miter router bit set that has both size router bits as well as a smaller version capable of using 3/8” to 1/2” stock? Isn’t the middle sized one completely unnecessary if the largest bit can cover the entire range of thicknesses?

I’ve got to be overlooking something so if you have experience with these and can enlighten me, I’d appreciate it!

Dan Russell

4 replies so far

View josephf's profile


216 posts in 2459 days

#1 posted 01-06-2019 05:23 PM

love the idea of it but hardly use mine .set-up is a job .seems a feeder is important for larger,longer projects . when they are used right they are so cool .fall into place ,lots of glue surface . had to do some columns for the front of a house years back ,i ended up using a drawer lock bit due to the lumber not being perfectly flat . I have seen cabinets guys with a shaper dedicated to this bit ,that would be a cool tool in the shop .I say -Try it out ! they sure have potential .

View Rich's profile


4419 posts in 952 days

#2 posted 01-06-2019 05:57 PM

The smaller Infinity bit is advertised to go down to 3/8”, but can do stock as thin as 5/16”. Your choice of size depends on what you will be using it for.

Regarding set up, lots of users struggle with getting it set right. The challenge is that there are two settings. One is the bit height and the other is the fence setting. Fortunately they are independent and changing one does not affect the other. Knowing that, you can choose one setting and get it right, then using a similar technique get the other one set.

The beauty is that, at that point, all you have to do is make two measurements and set up a formula based on the thickness of the board and you will be able to get it set for any thickness of board without test cuts.

Here is a blog post I wrote about it:

-- Knowledge is not skill. Knowledge plus ten thousand times is skill. -- Shinichi Suzuki

View Fred Hargis's profile

Fred Hargis

5507 posts in 2856 days

#3 posted 01-06-2019 06:28 PM

The largest Infinity lock miter is truly massive. Almost 3” across and weighs almost as much as a big panel raiser. If you look closely at the side by side pics you see it takes a much bigger bite: the tongue is larger; maybe too large for thinner stock. The size means it runs more slowly, I haven’t tried it on thinner stock….but I don’t think I want too. That said, I do think you probably do thinner stock on the large bit…at least down to 5/8” or so. I only see 2 sizes, did I miss something?

-- Our village hasn't lost it's idiot, he was elected to congress.

View AlaskaGuy's profile


5240 posts in 2672 days

#4 posted 01-06-2019 06:54 PM

Have your say...

You must be signed in to reply.

DISCLAIMER: Any posts on LJ are posted by individuals acting in their own right and do not necessarily reflect the views of LJ. LJ will not be held liable for the actions of any user.

Latest Projects | Latest Blog Entries | Latest Forum Topics