Forage des roches — Matériels pour forage percutant de longs trous — Équipements à filetage à butée inverse 1 1/16 et 1 1/4 in (27 et 32 mm)

Specifies the basic dimensions for equipment. Gives a list of components; tabulates together with figures: shank adapters for central flushing, hexagon type and lug-shank type; extension rods; coupling sleeves; four-wing bits; reverse-buttress threads; hollow hexagonal bars for extension rods; hexagonal drill-steels.