4.2.2 Piston rod chromating and surface hardness .
Eternal company ensure that every piece piston rod would be surface hardened before chromating ,
surface hardness is HRC55~60 , Chromating film thickness is 0.03~0.04mm if there is no other specific
4.3 Seal ring and O ring
According to the customers’ requirements and working condition , eternal company would choose suitable
seal ring kit , seal ring brand include :Parker , Merkel , NOK , Guangzhou Rubber institute , Taiwan brand etc . Eternal company would supply suitable seal solution for their customer so that hydraulic cylinder has more
lifetime , easy maintenance and simple repairing .
4.4 Tube and flange welding
The welding on cylinder tube and flange would be Ultrasonic tested every time , the welding seam would be
cleaned before machining .Eternal company ensure that every welding seam has no any leak during lifetime