US Patent 7575255 Wedge thread with high-angle metal seal

A threaded connection includes a pin member providing a single external thread comprising a first external portion and a second external portion, a box member providing a single internal thread comprising a first internal portion and a second internal portion, and a radial metal-to-metal seal to seal between the pin member and the box member, wherein the first and second internal portions threadably correspond with the first and second external portions, and wherein the first internal and external portions are characterized by a first wedge ratio and the second internal and external portions are characterized by a second wedge ratio, wherein the first wedge ratio is less than the second wedge ratio.