Abstract: Well apparatuses with device for preventing their relative rotation with respect to adjacent well apparatuses and anti-rotation devices for well apparatuses, including, but not limited to, plugs, float shoes, float collars, jars, and clutch devices for packers. In one embodiment self-aligning non-rotation devices are provided with body members having protrusions extending from recesses therein, the protrusions and recesses configured and disposed so that two opposed devices which initially misalign will co-act to align themselves. In another embodiment an intentional "sloppy fit" is provided between two opposed devices to facilitate device contact and co-action. In various embodiments unwanted separation of two devices is prevented due to the configuration of protrusions.

Abstract: A tong, preferably a power tong, with one or more floating jaws which are releasably retained on and selectively movable with a rotary device; in one aspect the jaws having a compound jaw camming surface with a primary cam action surface, a rest surface, and a fixed positioning surface; and in one aspect such a tong with a releasably jaw urging system for releasably urging the jaws against camming jaw rollers.

Abstract: A tool for milling a down-hole casing or tubing comprising a tubular body rotatable about its longitudinal axis and having a longitudinal passage therethrough. Means is provided at a first end of the cylindrical body for connection to a drive means to rotate the body. The first end forms the upper end of the body in the working position. At least one first blade extends outwardly from the cylindrical body and has a lowermost cutting edge extending upwardly from its innermost portion at an angle of from about 2.degree. to about 60.degree. to a radial plane perpendicular to said longitudinal axis, and at least one second blade extends outwardly from the cylindrical body and has a lowermost cutting edge extending downwardly from its outermost portion at an angle of from about 2.degree. to about 60.degree. to a radial plane perpendicular to said longitudinal axis.