Hollow-stem augers are frequently used for geotechnical exploration. One reason they are used is that the method is considered a “dry” drilling method where drill fluids are not needed to advance the borehole in unstable formations. Often, hollow-stem augers are used with other sampling systems, such as split barrel penetration resistance testing, Test Method D1586, or thin-wall tube sampling, Practice D1587 (see 2.5).