Hollow Stem TRI-LOK™ Auger Section

The TRI-LOK™ series offers tapered heavy-duty couplings with three chamfered, deep set, key ways and twin high-tensile lock bolts with sure grip heads for easy make and break. This exclusive design provides full torque loading throughout the heat treated coupling by dispersing the power equally to the three key ways. This ensures that the lock bolts only function in vertical auger removal.

The hollow-stem auger is used to advance and case the hole simultaneously. It may be used with or without a plug assembly depending on the job requirements. When a plug is used for the purpose of keeping soil from entering the mouth of the lead auger, it is held in place by center (drill) rod and rod to cap adapter, pinned in the drive cap. Upon reaching the sampling depth, the center rod with plug and pilot bit attached is removed from the mouth of the auger and replaced by a solid/split barrel soil sampler or tube sampler, lowered to the bottom of the hole through the hollow stem of the auger and sampling or coring is initiated. The use of a hollow-stem auger without the plug has shown that most clay type material will form its own 2"–4" (51– 102mm) plug which can be driven or washed through for sampling or core barrel operations. When flowing sands are encountered, mud may be added inside the hollow stem to serve as a “head” to equalize the hydrostatic pressure in lieu of the plug assembly. Hollow-stems are rotated dry and often to depths of 300 feet (91.4m). Many special applications can be carried out in addition to full range soil sampling. Piezometer and well point placement, slope indicator placement, cathodic protection devices, water wells, ground water monitoring wells, diamond drilling, anchor bolt placement as well as grouting and blast hole loading are some of the jobs that hollow-stem augers facilitate