[[Image:Auger drilling in action.jpg|thumb|right|250px| Auger drilling in action]]
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[[Image:Auger drilling in temporary casing1.jpg|thumb|right|250px| Auger drilling in temporary casing]]
The hand auger is suitable for unconsolidated formations: sand, silt and soft clay. Stiff clays, hard materials and gravels are difficult or impossible to drill through and to remove (unless augering is combined with [[percussion - general|percussion]]).
The hand auger consists of extendable steel rods, rotated by a handle. A number of different steel augers (drill bits) can be attached at the bottom end of the drill rods. The augers are rotated into the ground until they are filled, and then lifted out of the borehole to be emptied. A different auger can be used for each formation (soil) type. Hand augering can be done both by using a heavy tripod and winch (such as the [[Hand auger - Vonder rig | Vonder rig]]), or with lighter materials.
==Suitable conditions ==
[[Image:Auger drilling in temporary casing1.jpg|thumb|right|250px| Auger drilling in temporary casing]]
The hand auger is suitable for unconsolidated formations: sand, silt and soft clay. Stiff clays, hard materials and gravels are difficult or impossible to drill through and to remove (unless augering is combined with [[percussion - general|percussion]]).
Augers can be used up to a depth of about 15-25 meters, depending on the geology.
{{procontable | pro=
- Easy to use above the groundwater table <br>
| con= - It may be very difficult to remove the temporary casing. If clay layers are penetrated, it is very difficult to use a temporary casing, as it sticks to the clay. <br>
- The borehole does not stay open if a collapsing sand layer is encountered below a clay layer (through which the temporary casing could not penetrate)
}}
