An increment borer is a specialized tool used to extract a section of wood tissue from a living tree

Tree

A tree is a perennial woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or trunk with clear apical dominance. A minimum height specification at maturity is cited by some authors, varying from 3 m to...

 with relatively minor injury to the tree. The tool consists of a handle, an auger

Auger

An auger is a drilling device, or drill bit, that usually includes a rotating helical screw blade called a "flighting" to act as a screw conveyor to remove the drilled out material...

 bit, and a small, half circular, metal tray (core extractor) that fits into the auger bit. The auger bit is usually manufactured from carbide steel. It is most often used by forester

Forester

250px|thumb|right|Foresters of [[Southern University of Chile|UACh]] in the [[Valdivian forest]]s of San Pablo de Tregua, ChileA forester is a person who practices forestry, the science, art, and profession of managing forests. Foresters engage in a broad range of activities including timber...

s, researcher

Researcher

A researcher is somebody who performs research, the search for knowledge or in general any systematic investigation to establish facts. Researchers can work in academic, industrial, government, or private institutions.-Examples of research institutions:...

s, and scientist

Scientist

A scientist in a broad sense is one engaging in a systematic activity to acquire knowledge. In a more restricted sense, a scientist is an individual who uses the scientific method. The person may be an expert in one or more areas of science. This article focuses on the more restricted use of the word...

s to determine the age of a tree. This science is also called dendrochronology

Dendrochronology

Dendrochronology or tree-ring dating is the scientific method of dating based on the analysis of patterns of tree-rings. Dendrochronology can date the time at which tree rings were formed, in many types of wood, to the exact calendar year...

. This enables the user to count the rings in the core sample to determine the age of the tree or the growth rate of the tree. After use the tool breaks down and the auger bit and extractor fit into the handle. This makes it highly compact and easy to carry.

Use

Effective use of an increment borer requires specialized training. Samples are taken at breast height or stump height of the tree depending on the user's objectives. During use the borer should be well lubricated; this makes the auger bit easier to use and helps to prevent the increment borer from becoming stuck in the tree.

Maintenance

Increment borers should be properly maintained to keep them in good working condition. They should be cleaned after use and dried before storing. Sharpening kits are also available and should be used when the auger bits become dull.

Types of borers

Increment borers come in different lengths and diameters and have different types of threads

Screw thread

A screw thread, often shortened to thread, is a helical structure used to convert between rotational and linear movement or force. A screw thread is a ridge wrapped around a cylinder or cone in the form of a helix, with the former being called a straight thread and the latter called a tapered thread...

. The most common diameters are the 4, 4.15, and 5.3 millimeter borers. There are two different types of threading: two threading and three threading. Two threaded bores are more appropriate for hardwoods because they auger slower; this creates more torque

Torque

Torque, moment or moment of force , is the tendency of a force to rotate an object about an axis, fulcrum, or pivot. Just as a force is a push or a pull, a torque can be thought of as a twist....

when auguring into the tree. The three threaded auger will maneuver into the wood much faster than a two threaded auger.