Augers for Soil Testing

Hand Augers

• Hand augers are useful for shallow soil sample collection and borehole creation. A hand auger consists of a 1- to 2-foot stainless steel tube, or bucket, with angled teeth on the bottom that cut through the soil as it advances. The auger bucket attaches to stainless steel poles and a T-handle via bolts or rod pins. You can increase the depth of the borehole by adding more poles. To operate the hand auger, twist the T-handle while pushing downward. As the auger fills with soil, pull the auger from the ground and empty the soil. Your physical strength determines hand auger depth limits.

Hand-operated Power Augers

• Hand-operated power augers operate by small motors. You control the location and operation manually. The auger itself looks like a large, spiral drill bit. These augers are often approximately 3 feet long. Power augers come in one- or two-person designs. These types of augers can drill deeper than hand augers because of the motor although your physical strength and the soil type will also be a factor for some models. Power augers are useful for subsurface soil boring and sample collection when you are not installing a well.

Hollow-stem Augers

• Hollow stem augers are large, spiral augers that you operate with a drill rig. A drill bit on the bottom of the auger cuts through the sediment. Soil cuttings travel to the surface on the spiral edges. Hollow stem augers are often 5 feet long and have a hole down the center. Because the center of the auger is hollow, you do not have to remove the augers from the ground to collect a soil sample. Therefore, these augers are a popular choice for soil samples from moderate depths using tools such as split-spoon samplers and Shelby tubes. Hollow-stem augers are effective in unconsolidated soil, sand and clay, but they will not cut through solid rock.

Solid-stem Augers

• Solid-stem augers operate using a drill rig. These augers are able to cut through competent materials and are useful for well installation and exploratory drilling to significant depths. A drill bit at the end of the lead auger cuts the sediment as it advances. Solid-stem augers are often 5 feet in length and expel soil cuttings as they twist into the subsurface. To collect a soil sample using a split-spoon, Shelby tube or similar method, you must first completely remove the augers from the ground. Therefore, the subsurface material must be competent enough that it does not collapse into the borehole for this to be a useful soil sampling method.