Surface/face problem after intersect

Hello to all.
I need to cut a hole into a cylinder.
But when I did it my cylinder surface is ragged.
How to fix that problem? Is it a problem with geometry?

Do you have any idea?

You’re seeing the result of intersecting two polygons. Since SketchUp approximates circles with polygons (24-sided by default) and since the vertices don’t line up with the two cylinders, you’ll get that. You can reduce the appearance of jaggedness by increasing the number of sides used for the circles from which you make the cylinders. Just don’t go overboard on the number of sides. there’s a point of diminishing returns.

thanks a lot DaveR