Fatigue-resistant thread form that enhances the connection
The Grant Prideco™ SST™ thread form involves a modification to the pin thread only; the mating box thread remains unchanged. Completely interchangeable with standard API connections, Grant Prideco SST requires no crossovers or special rig handling procedures.
The SST pin incorporates two primary features. First, the thread form has an enlarged root radius. Second, the pin thread body is machined on a slightly flatter taper than that of the box, effectively behaving like a variable pitch thread.
These SST features provide improved fatigue life, and the reduction in stress at the pin thread roots and in the load at the last engaged thread enhance the performance of the connection.