Sandvik 905 165 09 Shank

The shank, part 905 165 09, receives the blows of the piston on its striking face and passes both that impact and the rotation of the drill on into the drill string, so it works at the point where the machine's energy first leaves it. It is a hardened steel part designed to take enormous repeated shock, and the condition of its striking face has a direct effect on how much of the piston energy reaches the rock.

A striking face that has mushroomed, dished or developed surface cracks no longer receives the blow squarely, and the shock that is not transmitted forward is reflected back into the machine, shortening the life of the piston and the rest of the percussion mechanism. The splines and the thread should be inspected as well, since fatigue cracks tend to start at the root of the thread and then run across the section without warning. Use a shank with the correct length and spline form for the rock drill, because a mismatched one changes the impact point and damages the front end. Stalroc quotes this Sandvik reference by part number and exports worldwide to mining, quarrying, and drilling contractors.