Stress-free, constructive screw anchor with round flat head with a head diameter of 18 mm for sufficient clamping force with slot holes of 13 mm, e.g. for attaching (GB) corner anchors. Suitable for heavy loads and small HOH and edge distances. For concrete, sand-lime brick and masonry. Integrated pressed-on flange with locking profile under the head. Dimensions on the top of the anchor stated for possible inspection. Attractive finish for visible work.