offer me new kind of cutting tool


i want to put a cut on this object above but the cuts available just in z and x how can i have a cut except pressing ctrl+r and knife ?!

K = knife
W / subdivide

Please show exactly what you want. What is wrong with the knife ?

i cant make cuts i blank area my mean is that a face that its did not have mesh and cut for example i want to draw a circle over the picture above there as i point it .

I - inset face probably will do what you want here.
K - knife tool needs 2 connections with polygon sides to work properly. You could start cut from one side, make circle or any other connected cut; after you hit Enter, second connection with some side will be drawn automatically.

thank you its useful for me how can i change mesh from different type to circle (except alt + shift + s an type 1) ?!!