Fluid divider block suitable for use at high pressures

The invention is a divider block assembly suitable for use at high fluid pressures. Applicant has found that a sufficiently deep counterbored hole allows a mounting bolt to apply the sealing pressure well below the divider block surface, which can reduce or eliminate the compressive force on the metal around the piston bore, thereby reducing or eliminating distortion of the piston bore of the divider block and providing.