A connection for tubulars

摘要

A connection, for use in joining tubulars, comprises a pin 10 which is configured for insertion into a box 12. The pin 10 and box 12 have an engaging area to allow them to be torqued together. At least one of an outer surface of the pin 10 or an inner surface of the box 12 has undergone surface treatment to provide a locking surface, which comes into contact with the opposing surface as a result of a radial expansion. A seal 17 may also protrude form one of the inner or outer surfaces and a clearance between the inner and outer surfaces to one side of the seal 17 may be eliminated by the radial expansion. The surface treatment may comprise the provision of a number of projections, parallel ridges or a diamond pattern.