Chromium Coated TFS Steel Sheet 0.20mm Thickness For Aerosol Can End Closures

Tin free steel, also called TFS or electrolytic chromium coated steel, is the lacquered-can specialist of the packaging steel family. Instead of tin, the surface carries a duplex coating of metallic chromium topped by a thin chromium oxide layer, both deposited electrolytically on a low carbon steel substrate. The result is a material that costs less than equivalent tinplate, adheres to organic coatings more strongly, and does not produce the iron sulphide staining that limits tin in protein rich packs.

TFS is supplied at 0.18mm to 0.25mm in T4 or DR8 temper, with a bright surface and tightly controlled roughness. Because the chromium layer is thin and non-sacrificial, the material is intended for fully lacquered applications rather than bare contact with food. In exchange it gives can makers a harder, more abrasion resistant surface that survives coil handling, blanking and high speed press feeding with fewer scratches, and it gives coating suppliers a chemically stable base on which lacquer weight and cure windows can be predicted accurately.

• Superior Paint Adhesion: The electrolytic chromium and chromium oxide duplex layer bonds to organic coatings more strongly than tin does, so applied lacquers and print resist detachment during end forming, scoring and the aggressive shaping of aerosol domes and crown caps.
• Excellent Sulfide Stain Resistance: TFS does not form iron sulphide stains the way tin does, making it the preferred substrate for lacquered food ends, meat and fish can lids and any pack where the interior will be coated and the appearance on opening matters.
• Cost Advantage Over Tinplate: Chromium is applied at 50 to 80 mg/m2 of metallic chromium plus 5 to 15 mg/m2 of chromium oxide, a far thinner coating than electrolytic tin, so the material is priced below equivalent tinplate while matching it in coated performance.
• Hard, Abrasion Resistant Surface: The chromium layer is harder than tin and resists scratching and scuffing during coil handling, blanking and feeding, reducing the surface defects that cause rejects on high speed end press lines.
• Consistent Formability For Ends: T4 and DR8 tempers cover both drawn ends and basic can ends, with uniform mechanical properties that keep score lines and rivet formations crack free on 0.18mm to 0.25mm gauges.
• Optimised For Lacquered Applications: Because TFS requires full lacquer coverage rather than relying on tin's sacrificial protection, the mill supplies the material with controlled surface chemistry and stable oil film so that coating weights and cure windows behave predictably on customer lines.

Typical uses are aerosol can ends and domes, beer and beverage crowns, lug and screw caps, twist off ends, drawn food ends and shallow drawn cans, plus general line closures where the interior is lacquered. It is widely specified for meat, fish and pet food ends because the absence of sulfide staining keeps the interior clean on opening, and for chemical and paint containers where the contents would attack a bare tin surface.

Can makers combining TFS ends with tinplate bodies benefit from a lower cost closure while retaining the same seaming dimensions, since TFS is produced to the same gauge and temper conventions. The material is also used for battery components, gaskets and small drawn parts where paint adhesion and hardness matter. Trial coils in 0.20mm T4 and DR8 are available with chromium coating weight certification so that coaters can confirm adhesion and cure performance before container orders.

Each coil is wrapped in anti-corrosion VCI film, interleaved with desiccant bags, then sheathed in kraft paper and finally enclosed by galvanised steel sheet with reinforced corner protectors. Coils are stacked eye-to-sky or eye-to-wall according to customer unloading equipment, strapped with PET bands at four points, and loaded into 20ft or 40ft containers on fumigated wooden skids. Sheet bundles are protected by edge boards and plastic strapping so that the surface finish reaches the destination port free of scratches, white rust and transit dents.

The mill operates under an ISO 9001 certified quality system. Every heat number is traceable and each shipment is accompanied by a mill test certificate covering chemical composition, tensile and yield strength, tin coating weight measured by coulometric stripping, and surface roughness. Third-party inspection by SGS, BV or Intertek can be arranged on request before container sealing, and a retained sample from each lot is archived for twelve months for future claim investigation. Any dimensional or coating non-conformity is settled by replacement or price adjustment within the contracted tolerance framework.