All it takes is a dash of colour to brighten up everything. Even our sheets. With the dream of making the world a brighter place, National Steel has introduced its flagship brand, KOLORMETAL. Manufactured with equipment from the world leader in colour coatings – Bronx Australia, KOLORMETAL has set a landmark in the Indian steel industry, and even commands credibility in the Global market. Available in a vast array of colours, KOLORMETAL is set to change the way the world looks at steel.

PPGI process is a roll coating process which consists mainly of cleaning, pre-treating, primer coating, finish coating and baking. No corners are cut in our endeavour to deliver the best to our customers. From cleaning to baking, every bit of care is taken to eliminate any drop in quality, even while maintaining our delivery timelines.

At National Steel we believe that one size or colour doesn’t fit all. In keeping with customer requirements, we manufacture different types of Roofing Sheets in various shapes. The sheets have large coverage and are suitable for several industrial applications. They are created with side lap corrugation which provides crucial support at the point of panel overlap, making them easy to install. To make the process even more seamless, our team of skilled professionals can efficiently install the sheets. Using Butyl tapes, which makes the structure weather proof, the team seals the specially-designed side lap anti-capillary grooves.

NSAIL’s Nationalume, the hot-dipped coating product is comprised of 55% aluminum, 43.5% zinc, and 1.5% silicon. This product is known by many different trade names throughout the world. Nationalume is one of the preferred names.

The aluminum-zinc alloy-coated steel sheet has proven to be an excellent product for long-life Roofing & Cladding, especially low slope roofing on industrial buildings.[ It has been widely applied as bare (unpainted) sheet with the coating being directly exposed to the atmosphere. ]

The product is also used as a substrate for prepainted sheet and this use has also grown significantly. The ASTM product specification for 55% Al-Zn coated sheet is A792/A792M, and the prepainted sheet version is specified in A755/A755M.

The resultant products are far superior in terms of adherence to zinc coating and surface finish. Furthermore, they meet international standards such as ASTM, JIS, EN and Australian as well as Indian standards.

[Corrosion performance data comparing the performance of 55% Al-Zn with galvanized coatings indicate that the performance is superior than galvanize coatings in all three types of environments– marine, industrial and rural.
The unique dendritic structure of the alloy coating is now widely recognized as the primary reason for the improved corrosion resistance of the 55% Al-Zn coating. When it is exposed to the environment, the zinc rich areas corrode first. Since these areas are located in a labyrinth of interdendritic regions in the coating, the products of corrosion tend to fill the interdendritic interstices and the corrosion rate decreases. This leads to a flattening, parabolic corrosion rate curve in most environments. This contrast with the linear behaviour typical of galvanize.
Corrosion of a 55% Al-Zn coating is therefore not the uniform thinning process of a galvanized coating.
During the early stages of the product life, the aluminum-rich dendrites are largely unaffected by most environments. In a sense, the aluminum-rich dendrites perform like a barrier coating, while the zinc-rich areas provide the galvanic protection that is needed to minimize the tendency for rust staining at sheared edges and other areas of exposed steel.]

NSAIL’s state-of-the-art cold rolling unit uses Canadian and Japanese equipment to manufacture annealed and galvanised cold rolled steel that is the best in its class, and adheres to global standards.

Cold rolling is done from hot rolled coil that has been trimmed and pickled before being rolled. The cold rolling process reduces the thickness of the steel and simultaneously changes/enhance the mechanical properties of the steel.

The cold rolled steel coils can then be annealed (heated in a controlled atmosphere) to make the steel more formable (cold rolled annealing) or further processed on the metallic coating line, with a coating of zinc (galvanising). Cold rolled steel is available in numerous grades, each with a variety of properties for different applications.

The resultant products are far superior in terms of adherence to zinc coating and surface finish. Furthermore, they meet international standards such as ASTM, JIS, EN and Australian as well as Indian standards.