[Cherryville Chuck]

There are some raised panel bits that were made in 1/4" shank that were meant to cut about 1/2" deep x 1 1/2" high but they should be used very carefully with numerous light passes to get to depth. I've used 3/4" in 1/4" shank but also with care and not too much depth per pass. I have broken a 1/4" shank or two in the past. 8mm has about a 30% larger cross section so I would agree with Pat that about 32mm would be the max and should be used carefully.

It does sound a bit like he was trying to part you from your money.

 

[Cherryville Chuck]

Esko, how long a bit with 8mm shaft are you wanting to use?

 

[Cherryville Chuck]

Hello guys.
From your question Charles rises a new Q. I'm making lapjoints to 2x4" or 4x4" with the router. I'm having an extended base or a XL base for the router so I have enough support for it. I'd rather use some thin material but I only had 15mm water ply. To be able to make flush joints I need to go 2" down, yes? So, 15mm&2" is
about 2 1/2" or 65mm. Shurly 3mm steel plate would be a better solution.

I understand all the if's and but's (my english is funny with all the faults but I know what I am doing and I know woodworking tools. I comleted my education in 1992). At the moment I just can't walk to the store and buy everything I need. Besides tools are quite expencive here in Finland.

Thank's for all the good advices and specially I'll keep in mind not to touch the spinning bit.

Esko, if the boards are based on the North American sizes then they will actually be 38mm x 89mm or 89mm x 89mm. There is a reason for this. Lumber is measured in the rough sawn condition which was a full 2 inches or 4 inches some years ago because of the crude saws used to cut lumber. Then the boards were planed to the dimensions above.

The longest bit you would need is 60mm plus the length of shank inserted into the router.

 

[Cherryville Chuck]

I should have considered you might measure differently. In our building code Imperial measure is listed as "nominal" measure and would be the rough sawn measure. However, when it lists metric measure it is in the actual dimension of 38 x 89mm for example. I'll be glad when we stop mixing the two systems together.

 

[Cherryville Chuck]

I've understood most of what you have tried to communicate. At least I think I did. I wasn't sure what you meant by:
"Then the boards were planed..."
If I buy planed 2x4"/50x100mm I could as well burn money in a stow. I would get one meter of 45x95mm. for 2.39 euros.