When coring in complicated geological conditions (regions of Karelia, Sochi, Crimea, etc.) used air percussion drilling complex SPK. Core pipe made strictly from high-strength steel and with increased wall thickness. On one side of the tube is connected to the drill string cutter adapter P1 Z-50 / TP-127 (tapered thread) on the back - with a crown pneumoshock KP-138.
Material - steel 40X