Wedge 521®

An integral semi-flush connection suitable for large-diameter surface casing, intermediate casing, horizontal liners, extended reach strings and drilling liners.

Special applications include drilling with casing, slotted liners for geothermal wells and rotation-while-bending during wash-down and cementing.


  • Available in sizes from 4" to 18 5/8".
  • High compression rating provided by the reverse angle stab flank of the dovetail threads makes the Wedge 521® suitable for the more severe compression applications.
  • Compression rating is typically 80–89% of the pipe body, and is usually higher than the tension rating.
  • Thread form provides 100% pipe body internal yield and collapse strength.
  • Excellent for large diameter pipe, the dovetail thread eliminates thread pull-out, even on thin wall pipe.



  • Deepwater
  • Shallow Water
  • Unconventionals
  • Horizontal and extended reach wells
  • Casing while drilling
  • Thermal (SAGD & CSS)
  • Geothermal
  • Intermediate casing
  • Production casing and liners
  • Surface Casing