Fast make-up fatigue resistant rotary shouldered connection

A thread form having a total thread height for securing together mating threaded components, comprising:

• a stab flank having a linear stab flank surface,
• a load flank having a linear load flank surface,
• a thread root surface connecting said linear stab flank surface and said linear load flank surface whereby said linear stab flank surface and said linear load flank surface define an included angle in a gap bridged by said thread root surface,
• a first surface of revolution, defined by a first radial length, included in said thread root surface,
• a second surface of revolution, defined by a second radial length, included in said thread root surface, said second radial length being greater than said first radial length,
• first and second centers of revolution for said first and second radial lengths being disposed on the stab flank side of a bisector of said included angle, and
• said thread form having a total thread height less than 7 times as great as its root truncation length.

A thread form for securing together mating threaded components, comprising:

• a helically developed thread tooth extending axially over a central thread axis,
• a stab flank having a first linear stab flank surface,
• a load flank having a linear load flank surface,
• a thread root surface connecting said first linear stab flank surface and said linear load flank surface whereby said first linear stab flank surface and said linear load flank surface define an included angle in a gap bridged by said thread root surface,
• a first surface of revolution, defined by a first radial length, included in said thread root surface,
• a second surface of revolution, defined by a second radial length, included in said thread root surface, said second radial length being greater than said first radial length,
• first and second centers of revolution for said first and second radial lengths, respectively, being disposed on the stab flank side of a bisector of the included angle,
• a second stab flank surface comprising a linear flat lying along an angle different than said first linear stab flank surface, said second stab flank surface connecting said first surface of revolution with said first linear stab flank surface, and
• said second radial length being greater than the length of said second stab flank surface.

A connector having a multi-start thread configuration wherein at least one thread of the configuration comprises:

• a stab flank,
• a load flank,
• a thread root connecting said stab flank and said load flank whereby said stab flank and said load flank define an included angle in the gap bridged by said thread root,
• a thread root truncation length measured along the bisector of the included angle between the thread root and the apex of the included angle,
• a first surface of revolution having a first radial length included in said thread root,
• a second surface of revolution having a second radial length included in said thread root, said second radial length being greater than said first radial length,
• centers of revolution for said first and second surfaces of revolutions being disposed on the stab flank side of a bisector of the included angle, and
• said first radial length and said second radial length each being greater than said thread root truncation length with said first radial length being at least 60 percent of the length of said second radial length.