The invention relates to an anchoring system for anchoring in a drill hole. The anchoring system comprises a sleeve element and an expansion element. The sleeve element consists at least in some sections of a plastics material and is suitable for insertion into a drill hole. The expansion element comprises a threaded portion into which the sleeve element can be screwed and is suitable to radially expand the sleeve element during the screwing action. The anchoring system is characterized in that the threaded portion has a thread pitch which varies along the threaded portion.