ISO9001-2008 cert. barrel material:ST52,ST45,OR 27SiMn rod:#45 chrome-plated each cylinder is ... :690mm4.port diameter:M20*1.55.pin hole:30mm6.length between trunnion and pin hole:220mm7.seal,see attached pictureinspection: length,leak ... ,pressure inspection Piston Hydraulic Cylinder used for machinery and vehicle for Farming,Construction,forestry,engineering