As I explained in the previous post about the CMT 8mm collet extension chucks, if the largest collet your router accepts is 8mm, then you cannot use 12mm or 12.7mm (1/2″) shank bits. And there isn’t an extension chuck for 12mm bits that you can insert into your 8mm router. If we have a router in the router table that accepts 12 and 12.7mm collets, we can buy an extension chuck like the one in the photo on the left, with the shank attached to the chuck itself. This type of chuck comes with a 12mm or 12.7mm shank, and the problem is that with it, we can only use 12 and 12.7mm collets since the 6, 6.35, and 8mm collets are too small to use with this chuck.
You can also buy this type of extension chuck with 12 or 12.7mm shanks, but for 6.35 and 8mm collets, to ensure your 1/4″ and 8mm bits stick out enough above the table. But with these extensions, you won’t be able to use the 12 and 1/2″ collets.
The references for these one-piece chucks are:
Prices are from 2014 and are outdated.
For use with larger collets:
Shank 12mm collet chuck for 12mm collet -> 796.002.00 -> €32.71
Shank 12.7mm collet chuck for 12.7mm collet -> 796.001.00 -> €32.71
For use with smaller collets:
Shank 12mm collet chuck for 8mm collet -> 796.002.01 -> €32.71
Shank 12.7mm collet chuck for 6.35mm collet -> 796.001.01 -> €32.71
The catalog says they come without a collet, but the extender I bought of this style did come with one. I got confused here and also in the video. If you look at the CMT catalog, this particular model (the one-piece one) DOES come with the corresponding collet that is listed in the catalog. The two-piece ones are the ones that come without collets.
You can find the references and prices (outdated) for the collets below.
I have the 12.7mm one, and it allows me to use 12 and 12.7mm collets. So I believe the chucks for larger collets accept both larger diameter collets, and the chucks for smaller collets accept both smaller diameter collets.
In the case that your router accepts a collet for 10mm, 12mm, or 12.7mm shank bits:
In this case, the best option may be to buy chucks like the ones we saw for routers that accept up to 8mm collets, but in this case, they will have a slightly larger diameter shank.
What we do is choose one of the following reductions, the one that interests you based on the collets you have in your router:
Prices are from 2014 and are outdated.
Shank diameter reduction S=10mm and metric M12 -> 797.100.00 -> €11.18
Shank diameter reduction S=12mm and metric M12 -> 797.120.00 -> €11.18
Shank diameter reduction S=12.7mm and metric M12 -> 797.127.00 -> €11.18
With any of these reductions, you can use any of the following chucks, so if you buy both chucks, you can use all the collets:
M12 metric collet chuck -> 796.000.00 -> €18.97
(For use only with 6, 6.35, 8, and 9.5mm collets)
M12 metric collet chuck -> 796.121.00 -> €20.40
(For use only with 10, 12, and 12.7mm collets)
So, if you have a router that accepts at least 10mm collets, by purchasing just one reduction and two chucks, you have a collet extension for all collets and, therefore, for all bit diameters between 6 and 12.7mm. The reduction, chuck, and collet assembly would be similar to the one shown in the upper photo.
As you can see in the following photo, the router collets and the collets used by these chucks are different, so you have no choice but to buy them as well:
Prices are from 2014 and are outdated.
6mm -> 796.560.00 -> €6.15
6.35mm (1/4″) -> 796.564.00 -> €6.15
9.5mm (3/8″) -> 796.595.00 -> €6.15
10mm -> 796.600.00 -> €6.15
12mm -> 796.620.00 -> €6.15
12.7mm (1/2″) -> 796.627.00 -> €6.15
