Free-fall drilling is the most ancient way of drilling in the world, but because of its simplicity and minimal cost relevant to this day in regions with loose and loose rocks.
Bailer is a tube with welded fork key and shoe with opening valve.
Length - 2.0 m
Diameter - 89 mm
Pipe material - steel 20
Shoe material - steel 40X
Connection - lock (cone) thread Z-63.5