Patent ID: 8869739

Claim:
A plug for insertion into a dovetail slot of a turbine wheel, the plug comprising: an insertion part shaped to be axially inserted into the dovetail slot from a turbine wheel face to a predetermined insertion depth when the plug is fully inserted into the turbine wheel; and a protrusion part shaped to axially protrude from the turbine wheel face when the plug is fully inserted into the turbine wheel, wherein the protrusion part comprises: a blast portion connected to the insertion part; and a shadow portion on outside of the blast portion, wherein a first contour of the shadow portion is defined at the turbine wheel face, wherein a second contour of the shadow portion is defined at a predetermined protrusion distance from the turbine wheel face, the second contour being outside of the first contour, wherein a shadow surface is a surface of the shadow portion between the first and second contours, and wherein a shadow angle formed between the shadow surface and the turbine wheel face is less than 90°.