A tip or those using AutoCAD 2011 hatch patterns. In the new 2011 version you can modify hatch dynamically without having to test out different scales via the command line.
Give it a try!
Click to select your hatch. From the contextual hatch editor tab, using a hatch grip (center of your hatch pattern) – just simply hover the cursor over the grip and choose the editing operations from the drop down.
Here is a quick animation how you can modify hatch is AutoCAD 2011 graphically on You Tube. It also shows you how to preview your hatch patterns directly inside your drawing boundaries before adding the AutoCAD Hatch Pattern.