Tinplate, Tin Mill Products, Specialty Metals, and Cold Rolled Steel

Tinplate is light gauge steel that is electrolytically plated with commercially pure tin for enhanced corrosion protection.  It is available in either a highly reflective bright surface, or as a non-reflective matte finish.  Tinplate is highly formable, drawable, and weldable making it suitable for a wide range of canmaking technologies.  Because of its corrosion resistance, a wide variety of food products can be packed in tinplate cans.  Tinplate is ideally suited as a base metal for lithography and organic coatings for items such as decorative tins, aerosol cans, and paint cans.

Tin Free Steel Commonly called TFS, tin free steel is actually a light gauge, electolytically coated chromium sheet.  It is a more economic alternative to tinplate, primarily used for can ends.  TFS is an excellent base for organic coatings and lithography.  In addition to can ends, TFS is also used for lockseamed can bodies, as well as numerous non-container items.

Black Plate is a light gauge cold rolled sheet steel and is the base metal for all tinplate and TFS.  Some manufacturers use black plate in its uncoated state for a wide array of products, such as curtain rods, building supply products, and toys, among other applications.

Hot-Dip Galvanized (HDG) is carbon steel that is coated with zinc on both sides of the steel in a continuous hot-dip galvanizing process. The process results in a layer of molten zinc being applied to each side of the sheet through the formation of an iron-zinc alloy bonding layer that is formed by a diffusion process while the heated steel comes in contact with the molten zinc allowing it to adhere to the steel.  

Hot-Dip Galvanized can be used in numerous different applications including, roll and brake-formed applications, lock-seam and deep drawn applications. In the most common applications it is joined by various methods including but not limited to the use of adhesives, riveting, soldering and welding. The different applications will require a different amount of galvanized coating due to the specific application with expectations of lengthening the life expectancy of the manufactured products. 

Some examples of some common applications include:

• Steel Studs
• Air Conditioners / Furnaces / Duct Work / Hot Water Tanks
• Automotive parts from body panels to frames
• Various building panels including walls and roof systems
• Electrical boxes
• Appliances including refrigerators, freezers, washers, & dryers etc.
• Light fixtures
• Mailboxes

Galvannealed (Galvanneal) is carbon steel that is coated with zinc on both sides in a continuous hot-dip galvanizing process.  After the steel exits the process where the molten zinc is applied, the molten zinc coating is exposed to an in-line heat treatment process that converts the coating into a zinc-iron alloy.   The galvannealed steel surface appearance resembles a non-spangled matte finish, a finish very different than the highly metallic appearance of the galvanized coating often observed on Galvanized HDG trash cans.  Galvanneal coating may appear similar to cold rolled steel, but with a superior resistance to rusting.

Galvanneal coated material easily accepts paint with a superior finished appearance. It can be painted without a surface pretreatment, but the use of a pretreatment will enhance the longevity after painting.

A benefit to using Galvanneal over Galvanized is that Galvanneal can be more easily welded and that the coating itself is far more resistant to damage and or scratching when compared to Galvanized (HDG) therefore providing additional corrosion resistance over Galvanized. 

Some examples of some common applications include:

• Automobiles – Exposed and unexposed parts.
• Garage Doors – due to the protection it provides from the elements as well as the excellent paint adherence.
• Fence Posts

Cold Rolled is a flat rolled steel sheet that is reduced to its final thickness by being rolled at room temperature.  It is used in many different applications such as storage racks, office furniture, tubing, and storage sheds.  Cold rolled is usually used as a painted product.

Hot Rolled is a steel sheet that is reduced to its final thickness on a high temperature hot rolling facility.  Used in items such as auto and truck frames, pipe and tube, and guardrail.  Hot rolled can be produced in a wide range of strengths, depending on its use.