Built tough enough to stand up to the roughest conditions. Pins and retainers: high tensile steel, zinc plated to prevent corrosion, comes with cotter pin retainers. Ports: double ported NPTF for greater flexibility of assembly, unless otherwise stated, cylinders assembled with ports inline. Piston nut: heavy duty automation grade self-locking piston nut holds piston in place under high cycle loading. Piston: ductile iron, precision machined providing a malleable bearing surface for extended cylinder life. Piston seal: 90 durometer O-ring with anti-extrusion back up washers provide sealing under high load conditions. Tie - rods: high tensile steel to prevent failure under high pressure. Cylinder shaft: high strength, hard chrome plated shaft provides extended cylinder life in harsh applications. Tube: precision finished skive and burnished heavy wall steel tubing for extended seal and cylinder life. Tube seal: 90 durometer o - ring with anti - extrusion back-up washer to prevent leakage under high pressure and cycle loading. Rod seal: Premium Double Lip Polyurethane BS profile using a double lip design for leak - free performance throughout the pressure range and longer life expectancy. Rod cap and clevis cap: ductile iron comes with drilled oil passages, offering increased bearing surface for high shock and side load applications. The Rod wiper: Polyurethane (AN or D style) proves a tough/hard material to remove contaminants from shaft surface. Threaded shaft: (on ASAE cylinders) to accept optional mechanical stroke control (not applicable to 5? bore cylinders). Rod clevis: ductile iron comes with 360? thread contact area and positive set screw locking device able to withstand continuous high load without wear or fracture. All cylinders are 100% hydraulically tested up to two times working pressure.