Round nose Grab (clamshell) The mechanical round nose grab is specially designed for heavy-duty dredging. The shells and knives are manufactured in a round shape for more strength and more penetration power into the very hard soils mixed with rocks. The grab is manufactured of high wear resistant steels such as Hardox 400, Weldox 700 . The rotation points are equipped with heavy duty bearings. The bearings are double sealed to prevent entering dirt into the bearings. The shells are fitted with heavy-duty interchangeable teeth, which are easy and quick to replace. The grabs can be manufactured in any weight and capacity you require. In a two- or four rope execution.