Tin-Free Steel (TFS), also known as Electrolytic Chromium Coated Steel (E.C.C.S.), is a high-performance material designed for a wide range of applications in manufacturing and packaging. Its unique composition ensures durability, corrosion resistance, and excellent handling characteristics. Below, you’ll find detailed technical specifications and recommendations for optimal use.
Tin-Free Steel is a steel sheet coated on both sides with a dual-layer film comprising metallic chromium, chromium oxide, and oil. Each component contributes to the exceptional properties of TFS:
TFS is versatile and used in:
• Stamped parts, lids, and ends
• Oval and cylindrical two-piece cans
• Rectangular cans
• Crown caps for soft drinks and beer.
| Type | Features | Applications |
|---|---|---|
| D | Deoxidized for deep-drawn cans to prevent wrinkles during machining. | Two-piece cans, aerosols |
| L | Contains small quantities of metalloids and residual elements such as Cu, Ni, Cr, Mo. Improved corrosion resistance for specific food products. | Food cans |
| MR | Contains low percentages of residual elements. General-purpose steel with excellent corrosion resistance. | Various can types |
Tin free steel is designed and processed to be corrosion resistant, applying lithography coatings on both sides, however for best results, it is recommended to have into account the following points:
Store tin free steel with exceptional care with the humidity.
Never store tin free steel outdoor
Use tin free steel for a maximum of ten (10) days after having been unpaged.
Handle tin free steel with gloves. Fingerprints and sweat can be easily removed rubbing with an alcohol-impregnated cloth.
Do not store tin free steel in process, with lacquer or lithography on one side, for a period longer than one week.
| CHEMICAL COMPOSITION FOR STEEL USED FOR ETP | |||
| Elemental | Type D % max | Type L (1) % max | Type MR (1) % max |
| Carbon | 0.12 | 0.13 | 0.13 |
| Manganese | 0.60 | 0.60 | 0.60 |
| Phosphorus | 0.02 | 0.015 | 0.02 |
| Sulfur | 0.05 | 0.05 | 0.05 |
| Silicon (2) | 0.02 | 0.02 | 0.02 |
| Copper | 0.20 | 0.06 | 0.20 |
| Nickel | 0.15 | 0.04 | 0.15 |
| Chromium | 0.10 | 0.06 | 0.10 |
| Molybdenum | 0.05 | 0.05 | 0.05 |
| Others, each | 0.02 | 0.02 | 0.02 |
According to ASTM A623-2009. (1) Double reduction products are obtained in type L and MR.
(2) When it is used steel obtained by continuous casting killed by silicon it is accepted until 0.08%.
| FINISHES | |||
| TYPE | MAIN USES | FEATURES | |
| BRIGHT | General purpose cans | Finishing with melted tin, with a bright shine | |
| MATE | Crown caps | Matte finishes, without shine, with electrolytically deposited tin without melting on the matte finishes steel plate | |
| SILVER | Cans for different applications, crown caps | Finish with melted tin produced using a special treatment on the base metal | |
| STONE | General use cans | Finish with melted tin, produced on the base metal, with a slightly matte appearance. Resist scratching during lithography or cans production. | |
| TEMPER | Hardness, HR 30T | Thickness: e, mm | Uses |
|---|---|---|---|
| T1-BA | Max 53 | e ≤ 0,21 | Necks, nozzles, taps, toys bottoms for 5 gal. cans for oil and other uses that require deep drawing. |
| Max 52 | 0,21 < e ≤ 0,28 | ||
| Max 51 | e > 0,28 | ||
| T2-BA | 53 ± 4 | e ≤ 0,21 | Small, square cans, cans for fish (0) salted meat, rings and other uses, with moderate draw. |
| 52 ± 4 | 0,21 < e ≤ 0,28 | ||
| 51 ± 4 | e > 0,28 | ||
| T2.5-BA, CA | 56 ± 4 | e ≤ 0,21 | Crowns, for cans and other applications that require moderate draw and harness. |
| 55 ± 4 | 0,21 < e ≤ 0,28 | ||
| 54 ± 4 | e > 0,28 | ||
| T3-BA, CA | 57 ± 4 | e ≤ 0,21 | Bodies for 5 gal oil cans, large cans and other applications that require an appropriate level of hardness. |
| 56 ± 4 | 0,21 < e ≤ 0,28 | ||
| T4-CA (1) | 62 ± 4 | e ≤ 0,21 | Bodies and bottoms for cans that require relatively high strength, and crown caps. |
| 61 ± 4 | 0,21 < e ≤ 0,28 | ||
| T5-CA (1) | 65 ± 4 | e ≤ 0,21 | Bodies and bottoms for cans that require a combination of high hardness, strength, an good formability. |
| 65 ± 4 | e > 0,28 | ||
| DR 7,5 | 70 ± 4 | e ≤ 0,21 | Bodies and bottoms of small diameter cans requiring high strength. |
| 70 ± 4 | 0,21 < e ≤ 0,28 | ||
| 70 ± 4 | e > 0,28 | ||
| DR 8(2) BA – CA | 73 ± 4 | e ≤ 0,21 | |
| 73 ± 4 | 0,21 < e ≤ 0,28 | ||
| 73 ± 4 | e > 0,28 | ||
| DR 9(2) CA | 76 ± 4 | e ≤ 0,21 | |
| 76 ± 4 | 0,21 < e ≤ 0,28 | ||
| 76 ± 4 | e > 0,28 | ||
| DR 9 M (2) | 77 ± 4 | e ≤ 0,21 | |
| 77 ± 4 | 0,21 < e ≤ 0,28 | ||
| 77 ± 4 | e > 0,28 | ||
| DR 10 | 80 ± 4 | e ≤ 0,21 | |
| 80 ± 4 | 0,21 < e ≤ 0,28 | ||
| 80 ± 4 | e > 0,28 |
(1) CA means continuous annealing and BA means box annealing
(2) DR: Base metal produced using the double cold reduction process; provides greater stiffness and strength than conventional base material and, therefore, provides the same strength using smaller cross sections. These advantages make it possible to produce more cans per unit weight of electrolytic tinplate. Service characteristic, thickness distribution and chemical characteristics are like those of conventional Steel
| DIMENSIONS AND COATING AVAILABILITY | |||
|---|---|---|---|
| Variable | Units | Minimum | Maximum |
| 3.4.1. Mechanical Properties and Coatings | |||
| Thickness | mm | 0.15 | 0.6 |
| Temper | N/A | T1 | DR10 |
| Metallic tin | g/m² | 1.1 | 13.4 |
| Iron-tin alloy | g/m² | 0.4 | 1.2 |
| Chromium oxide (passivation) | µg/dm² | 40 | 70 |
| Oil | mg/m² | 0 | 25 |
| 3.4.2. Packages Presentation | |||
| Rectangular Cutting Sheets | |||
| Cutting length | mm | 457.2 | 1250 |
| Width | mm | 600 | 965.2 |
| Package weight | Kg | N/A | 2500 |
| Package height | mm | N/A | 450 |
| Pre-scroll Cutting Sheets | |||
| Thickness | mm | 0.13(1) | 0.50 |
| Cutting length | mm | 610 | 1016 |
| Width | mm | 610 | 1118 |
| Package weight | Kg | N/A | 2500 |
| Package height | mm | N/A | 457,2 |
| Rectangular Re-squared Cutting Sheets | |||
| Thickness | mm | 0.13(1) | 0.40 |
| Width | mm | 600 | 1000 |
| Cutting length | mm | 500 | 1000 |
| Package weight | Kg | N/A | 2500 |
| Package height | mm | N/A | 450 |
| lithographed sheets (Press) | |||
| With | mm | 710 | 1130 |
| Lenght | mm | 510 | 960 |
| Maximum printing area | mm | 1130(With) | 945(Length) |
| Package weight | Kg | N/A | 2500 |
| Package height | mm | N/A | 450 |
| Varnished sheets | |||
| With | mm | 710 | 1130 |
| Lenght | mm | 510 | 960 |
| Maximum printing area | mm | 1130(With) | 970(Length) |
| Package weight | Kg | N/A | 2500 |
| Package height | mm | N/A | 450 |
| 3.4.3 Coils Presentation | |||
| 3.1 Coils | |||
| Coil weight | Kg | 1000 | 9000 |
| Internal diameter | mm | 419 | 505 |
| External diameter | mm | 610 | 1626 |
| Strips | |||
| Thickness | mm | 0.17 | 0.6 |
| Coil width | mm | 600 | 984 |
| Strip width | mm | 20 | 614 |
| Strips by step | Units | 2 | 15 |
| Coil weight | Kg | 1000 | 9000 |
| Internal diameter | mm | 505 | —– |
| External diameter | mm | 610 | 1624 |
Sheets with thickness less than 0.15 mm are provided by the customer.
General recommendations
Apply a moderate quantity of lubricants in the fabrication process. Oil is an important constitutive layer of the tin free steel and should never be specified without oil.
Before any cutting or forming process, apply lacquer or varnish on both sides of the tin free steel to avoid friction problems associated with the chromium coating.
Use cutting and stamping tools with special steel, like carbon steel with tungsten, to avoid it fast wear.
If it is necessary to have the same tone of the lithography applied over tin free steel than the lithography applied over tinplate, it is necessary, in some cases, to change inks formulation or increase film thickness, among others. If these conditions are necessary, the standards should be modified, and the optimum formulation must be found before industrial processing.
Tin free steel could be used on products with less than 1% organic acids (acetic acid and lactic acid), provided that the tin free steel is coated with the appropriate lacquer.
When tin free steel will be used on bodies and bottoms for food cans, specific tests must be done to assure that coating materials and conditions are appropriate, because content and thermal treatment used are not uniform.
Do not use tin free steel for cans type DI – deep drawing.
In general the lots with greater area or quantity should be in the stack’s lower side
Stack height should be necessary enough to keep visual control to avoid injuries. Moreover, stability due the base/height and floor capacity resistant should be considered.
For more detailed technical information or to discuss your specific requirements, reach out to our expert team.
Let us help you select the optimal specifications for your project.
