Manufacturing Process

Unit of Tube Investments of India Limited



Pickling is a preparatory step where scales are completely removed from the surface ov hot rolled coils. Pickling is done at TPI through a push-pull high quality pickling line. Pickled coils are passed on to rolling mills after slitting or dispatched to users as HRPO after oiling.


Annealing is the process of heating, holding at a suitable temperature and then cooling at a suitable rate, for such purposes as reducing hardness, facilitating cold working and producing a desired micro structure. For obtaining the desired mechanical, metallurgical, physical or other properties, TPI is equipped with EBNER make (Austria) Bell Furnaces for annealing under controlled atmosphere of N and H.

Cold Rolling

Cold rolling is the process where strips are reduced to achieve the desired thickness, mechanical properties and surface finish. At TPI, this process is done using both 6Hi & 4Hi mills. Cold rolling mills are fitted with hydraulic automatic gauge control systems, which ensure uniform & close thickness tolerances. At TPI, Cold rolling mill capability is enhanced to produce CRCA strips up to 7.3 mm thickness in low carbon, medium carbon & alloys steels.

Packing and Shipment

Strips in coil and cut to length form are wrapped with waterproof VCI film and placed on a wooden pallet as per customer’s packaging requirement