Tubing is pipe used for the transportation of crude oil and natural gas from an oil or gas layer to the surface after drilling is complete. It is made to withstand the pressure generated from the extraction process. Tubing is manufactured in the same way as casing, except that an additional process known as "upsetting" is applied to thicken the pipes. The tubing production processing is similar to the process of casing production. Tubing pipes typically have diameters of 60.3 mm to 114.3 mm.