Reconditioning Piston Crowns “Machining takes place on CNC controlled turning machines which can automatically machine the parabolic crown top” Before starting the pre-inspection, the parts are cleaned by grit blasting or ultrasonic/chemical cleaning. During the pre-inspection all the dimension will be measured, and a dye check will be done to see if there are any cracks in the material. After pre-inspection an official inspection report and quotation is made, based on the reconditioning procedures approved by class. Before piston crowns are welded the ring groove section, outside/inner diameter and the combustion face of the crown will be pre-machined. All welding procedures are approved by Lloyds which includes: – Submerged Arc Welding (Automatic)– MIG/TIG Welding (Automatic/hand) After the welding the piston crown are heat treated (annealing) in our own one to release the welding stressesThe remaining chromium layer on the ring grooves will be machined out, and a new double chromium layer will be applied on the ring grooves.