Over 4 inches is fine if its a tool and you have reasonable use for it. I can carry a large machete across town if I am going to work clearing land of brush and such. I can also carry a larger knife for hunting/fishing purposes as well as sport or outdoor survival such as camping or hiking. I do wood carving so I often have a few knives, one over 4 inches, I am also looking for a small carving axe/hatchet for spoons/bowels and removing excess wood. It is legal for me to carry the knives and small axe to the waterfront downtown in order to carve boats and such on the pier.