5) Tempering
After the washing phase, the shanks pass through the furnace at a temperature between 300-500 ° C, with the aim of reducing the hardness of the shanks and increase the toughness and endurance. Hardness and toughness are the characteristics that the shanks must have in order to be used.
6) Tumbling
The shanks, after the tempering heat treatment, are submitted to the next stage of tumbling. The samples are stored in special containers vibrant (tumblers), which allow you to clean up by rubbing the shanks from burrs and slag from thermal treatment.
7) Packaging
The shanks, after the stage of tumbling, are ready to be shipped to the customer are then deposited in special cardboard boxes and stored in the finished product warehouse waiting to be shipped to the customer. Same procedure for the spines of steel rings at the end of the whole process will be sent outside for treatment of galvanizing and, back in bags through a special automated machinery.
