Appropriate bit

I want to do a little box somting like 33mm*33mm withe 45mm deep what type op bit is the best for that joob and how much daimeter?

If is a square or rectangular box then you can use a 1/16" bit for the first pass then use a smaller one if you have it such as the 1/32" to do a finishing pass.
This is for the inside of the box. The outside you can get nice corners with the 1/16 bit.
The two bits will not make sharp corners. You will need to use a chisel or similar tool.
If you do not care about the corner being too deep then you can set up with a 10° Vbit and set the DOC small.

I do a lot of small stuff myself. Just not boxes. :wink: