A drill string includes a plurality of tubular members each having a connection with a pin connector and a box connector on adjacent tubular members. The pin connector has an external thread with negative load flanks and positive stab flanks, adapted for threadingly engaging an internal thread second threads with negative load flanks and positive stab flanks on the box connector of the adjacent tubular member. The positive stab flanks have corner radiuses and the negative load flanks have radiuses forming a S-shape. The pin connector has an outer groove for receiving a protuberance on the terminal end of the box member forming locking shoulders. The protuberance and groove have contoured surfaces providing large metal-to-metal contact for preventing the contoured surfaces from sliding during over-torquing and cyclic bending of the drill string. The negative load flanks and locking shoulders lock the connection together. The negative load flanks absorbing the tension and the locking shoulders absorbing the compression on the connection.
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a divisional of U.S. patent application Ser. No. 09/371,562 filed Aug. 10, 1999 now U.S. Pat. No. 6,485,063 and entitled "Connection" which is a continuation-in-part of U.S. patent application Ser. No. 08/972,516 filed Nov. 18, 1997 now U.S. Pat. No. 6,047,997 and entitled "Connection" which is a continuation-in-part of U.S. patent application Ser. No. 08/648,406, filed May 15, 1996, now abandoned and entitled "Novel Locking Design", both hereby incorporated herein by reference.
An assembly including inner and outer overlapping annular elements with interengaging threads. An axial abutment between the two elements is spaced from the threaded section to permit a structural and fluid seal at the joint. Pilot joints are provided to stabilize the joint and provide additional sealing.
