John Martin Polished Rod Clamps are manufactured from forged, high strength steel. They are precision machined on both load-bearing ends as well as the polished rod through hole. The ends are machined perpendicular to the through hole to ensure that the polished rod load does not impart a side load to the polished rod. Only a pure vertically applied load can extend polished rod life to its designed maximum. Harbison-Fischer JM Polished Clamps are available in polished rod sizes from 1" through 1-1/2"
diameter.

   The John Martin Model 25 Polished Rod Clamp is a one bolt, rugged design clamp for intermediate depth wells. It is rated to 25,000 pounds maximum working load.

   The John Martin Model 13 Polished Rod Clamp is a one bolt clamp designed for shallow wells with less than 13,000 pounds maximum working load.

   The John Martin Model 13-D and Model 13-T Polished Rod Clamps are high load variations using the Model 13 clamp. Two Model 13 clamps are factory assembled in series to make the Model 13-D Clamp which is rated to 26,000 pounds maximum working load. Three Model 13 clamps are factory assembled in series to make the Model 13-T Clamp which is rated to 40,000 pounds maximum working load.