Pipe cutter

A pipe cutter (1) suitable for cutting the casing of a well bore, comprises a body (2) having a plurality of knives (4) pivotally mounted thereon and each rotatable between a storage position (as shown) in which the knives do not extend radially outwardly of the body and a use position in which the knives extend radially outwardly of the body to engage a pipe to be cut. Operating means (6A) are selectively operable to move the knives from the storage position to the use position. Biasing means (9, 11) are provided for biasing the knives into the storage position whereby when said operating means is not in use the blades adopt the storage position under the influence of the biasing means. The operating means and biasing means permit fluid circulation through the tool. Means (16A) are provided for holding the biasing means out of contact with the knives to facilitate knife removal.