Thread Datum Arbor Establishes Pitch Dia.

Indicator Checks Face For Squareness.

Thread Arbor Establishes P.D.

Valve Adapter is Rotated in Seat to Check Concentricity.

Thread Datum Chuck Locates Pitch Dia. Center.

Indicator Checks Ring Groove Concentricity.

Std. Zero VA Is Combined With Model C - 2 Thread Arbor For Concentricity Check.