A cork borer is a metal tool often found in biology and chemistry laboratories. It is used for boring holes in corks or rubber stoppers to insert glass tubing. It consists of a plated tubing with precision ground cutting edges.
Cork borers are also used in taking samples from trees for tree ring analysis and for obtaining samples for experiments where diameter is required. For instance, a cork borer is used in maintaining a constant surface area when testing the water potential of a potato. Other uses of a cork borer include punching holes in an agar plate, performing well diffusion essays in microbiology to study Bioactivity.