Wind turbine blade bushing system

A wind turbine blade bushing system for arrangement in a root end of a wind turbine blade, the wind turbine blade bushing system comprising:

• a threaded element for retaining a mounting bolt for a wind turbine blade, the threaded element being formed from a first material, wherein the threaded element is a bolt-receiving nut for receiving the mounting bolt for the wind turbine blade;
• and
• an anchor element for arrangement proximal to a root end face of the root end of the wind turbine blade, wherein the anchor element retains the threaded element in the wind turbine blade and anchors the wind turbine blade bushing system in the root end face of the root end of the wind turbine blade, the anchor element being formed from a second material, the anchor element extending from the root end face to a longitudinal position distal to the root end face, and wherein the anchor element comprises a tubular member for arrangement at the root end of the wind turbine blade to retain the tubular member in a wind turbine blade body, wherein the tubular member acts to at least partly retain the bolt-receiving nut in the wind turbine blade,
• wherein the tubular member comprises a first open end to receive a bolt, an internal chamber of the tubular member comprising a first constriction between a location of the bolt-receiving nut in the tubular member and the first open end so as to retain the bolt-receiving nut in the tubular member, the first constriction being sized and contoured to mate with an outer surface of the threaded element,
• wherein the tubular member further comprises a second end positioned opposite the first open end, the internal chamber of the tubular member further comprising a second constriction between the location of the bolt-receiving nut in the tubular member and the second end so as to retain the bolt-receiving nut in place relative to the second end of the tubular member, the second constriction being sized and contoured to mate with the outer surface of the threaded element, and
• wherein the first material has a higher strength and higher fracture toughness than the second material.