... , all seals are manufactured to US specification, and being 100% hydro-pressure tested before delivery. ... 7.Base End High tensile cast steel8.Piston nut(applicable for A type 1.5", 2"bore ... & applicable for B type) Jam nut, grade 8, high tensile zinc-plated9.PistonDuctile iron ... hydraulic cylinders, pistons, flanges, valves parts, casting and forging parts, engineering goods, etc.5. Quality control ...