Screw thread roller burnishing apparatus

An apparatus for burnishing an external screw thread, comprising:

• a support structure;
• first and second members connected to said support structure at spaced apart locations thereon and being movable relative to said support structure toward and away from one another;
• a pressure vessel operative to receive a pressurized fluid from a source thereof, said pressure vessel being anchored to said first member and having an extendable piston;
• first and second thread burnishing structures respectively carried by said first and second members for movement therewith relative to said support structure;
• and
• a linking structure, wherein a portion of said linking structure extends between said extendable piston of said pressure vessel and said second member, said linking structure being adjustable to (1) move said first and second members toward one another to bring said first and second thread burnishing structures respectively into contact with diametrically opposite side portions of the external screw thread, and (2) move said first and second members away from one another to move said first and second thread burnishing structures out of contact with the external screw thread, wherein said extendable piston is configured to extend out of said pressure vessel in a direction extending away from said first and second members and to retract into said pressure vessel in a direction toward said first and second members.