DTH Hammers, Overburden Systems

Updated: 07.05.2026
Overburden Bit
1 image

TRB overburden drilling systems are designed for drilling with simultaneous casing advancement. The wings are retracted by reverse rotation.

ModelCasing Size ODCasing Size IDCasing Size WallBit Ø ExpendedBit Ø RetractedNo. of WingsApplicable Hammer
mmmmmmmmmm
TRB 90114102.85.6126902TG 35
TRB 115141.3128.16.61571132TG 40
TRB 130148.7133.77.51551172TG 40
TRB 140168.3146.410.951761322TG 50
TRB 150177.81675.41881502TG 50 / TG 60
TRB 165193.1182.35.42031632TG 60
TRB 1902192009.52291802 or 3TG 60 / TG 80
TRB 215244231.46.32602132 or 3TG 80
TRB 240285265102992412 or 3TG 80
TRB 250301.6272.214.73122533TG 80
TRB 280335.9315.9103502923TG 100
TRB 315365331173723053TG 100 / TG 120
TRB 365406374164223503TG 120 / TG 125
TRB 410457.2425.2164773993TG 320
TRB 460508476165264523TG 320
TRB 510558.8539.89.55785103TG 450
TRB 560609.6584.212.76305543TG 450
TRB 610660.463512.76826053TG 550
TRB 660711.2685.812.77336443TG 550
TRB 710762742107827083TG 550
TRB 760813775198357423 or 4TG 550
TRB 810863819228747813 or 4TG 640
TRB 860914.4882.4169368354TG 640
TRB 9601,016986151,0549505TG 800
TRB 10601,219.21,168.425.41,2511,1256TG 800