摘要 |
The present invention relates to a drill rod for percussion drilling machines comprising a rod or a sleeve-shaped element that is provided with a threaded portion for engagement with another correspondingly threaded drill rod element. In order to reduce the risk for pitting damage, the threaded portion is provided with a wear lining that is metallurgically bonded to the rod. The lining is made of a metallic material that is softer than the material of the element, the latter usually being steel. |