Tin Plate is subject to the KS D 3516(or JIS G 3303) standard.  Prior consultation is recommended for other specifications. Tin plate and Black plate (excerpts from KS D 3516 or JIS G 3303)

1. Scope

This standard specifies two types of cold-rolled tin plates, single-rolled plates and double-rolled plates.  Single cold-rolled tin plates and black plates are made of carbon steel with nominal thickness of 0.15mm to 0.60mm.  Double cold-rolled tin plates and black plates are composed of low carbon with nominal thickness of 0.14mm to 0.36mm.

2. Classification and Code System

Classification and code system of tin plate and black plate are as follows. Classification KS JIS Black Plate SPB SPB   Electro-Plated Tin Plate ET SPTE Hot-Dipped Tin Plate HT SPTE

Marking method for two-sided, differential tin plating

In case of differential plating, marking side and marking method must be agreed upon beforehand and written in the ordering contract. Marking Method e.g. D A line with the width under 2mm shall be marked at the trimming edge of thin coating side.   5.6/2.8D A When marking on the thin coating side, a geometric-shaped line with the width of 1mm should be marked. 5.6A/11.2 When marking on the thick coating side, a parallel line with the width of 1mm should be marked. 5.6/11.2A

Tin Plating

Electro-plated tin plates can be classified into equal plating and differential plating, as shown in the below table. Code of Types Classification Coating Weight Code Nominal Plating Weight Average Weight, min. Code for Tin Plating(Reference) ET, SPTE Equal Plating 2.8/2.8 2.8/2.8 4.9 #25 5.6/5.6 5.6/5.6 1.05 #50 8.4/8.4 8.4/8.4 15.7 #75 11.2/11.2 11.2/11.2 20.2 #100 Differential Plating 5.6/2.8 5.6/2.8 5.05/2.25 #50/25 8.4/2.8 8.4/2.8 7.85/2.25 #75/25 8.4/5.6 8.4/5.6 7.85/2.25 #75/50 11.2/2.8 11.2/2.8 10.1/2.25 #100/25 11.2/5.6 11.2/5.6 10.1/5.05 #100/50 11.2/8.4 11.2/8.4 10.1/7.85 #100/75 HT, SPTH Equal Plating 12.3/12.3 12.3/12.3 19.0 #110 14.0/14.0 14.0/14.0 22.4 #125 15.1/15.1 15.1/15.1 23.5 #135 16.8/16.8 16.8/16.8 26.7 #150

3. Temper Quality

Single Rolled Product

Temper quality of single cold-rolled tin plate and black plate is expressed with Rockwell Harness number, Scale-T (HR30T).  The set targets are given in the table below.  If purchaser wants temper quality other than the given ones, it can be manufactured with prior consultation. Code Target Rockwell Harness T scale, HR 30T T-1 49±3 T-2 53±3 T-2.5 55±3 T-3 57±3 T-4 61±3 T-5 65±3 Remark 1. Temper quality of single cold-rolled tin plate and black plate cannot be exactly defined with only one mechanical property.  However, Rockwell harness number T-scale has been adopted as it is a useful and reliable indicator of mechanical properties.  2. It is possible to anneal either with box annealing method or continuous annealing method.  Even if the hardness value is equal, other mechanical properties may differ according to the applied annealing method.  Thus, purchaser may select the annealing method after close consultations with manufacturer.  If continuous annealing method was selected, the letters "CA" is added to the temper class code (e.g:T-4CA).  3. Unless otherwise specified by purchaser, the hardness value of each temper class may be lowered, considering the age-hardening caused by storage conditions before tin coating.

Double Rolled product

Temper quality of double cold-rolled tin plate and black plate is presented with the Rockwell Harness value, Scale-T (HR30T). The set targets are given in the table below. Code Target Rockwell Hardness scale-T(HR30T) Target Proof Stress (Reference) Rolling Direction kgf/mm2(N/mm2) DR-8 73 56(550) DR-9 76 63(660) DR-9M 77 67(660) DR-10 80 70(690) Remarks 1. Temper quality of double cold-rolled tin plate and black plate cannot be exactly defined with only one mechanical property. However, Rockwell harness number T-scale has been adopted as it is a useful and reliable indicator of mechanical properties. 2. Proof stress value can be used as a reference when needed. The value has been calculated from the spring back test result. 3. It is possible to anneal either with box annealing method or continuous annealing method. Even if the hardness value is equal, other mechanical properties may differ according to the applied annealing method. Thus, purchaser may select the annealing method after close consultations with manufacturer. If continuous annealing method was selected, the letters "CA" is added to the temper class code (e.g:T-4CA).

4. Surface Finish

Electro-Plated Tin Plate

The surface finish of electro-plated tin plate is classified according to the finishing method used after plating. Product Code Classification Features Single Rolled B Bright Finish Lustrous surface is created by flow-brightened tin coating spread on the smooth grindstone-finished black plate. R Stone Finish Flow-brightened tin coating is applied onto the black plates with directional grindstone pattern surface finish to bring lustrous shine. S Silver Finish Flow-brightened tin coating is applied to the rough dull-surfaced black plate, giving it lustrous shine. M Matte Finish Non-melted coating is done onto the dull surface finished black plate. Double Rolled R Stone Finish Flow-brightened tin coating is applied to the black plate with directional grindstone pattern surface finish to bring lustrous shine.

Black Plate

Surface finish for black plate is classified as below. Product Code Classification Features Single Rolled B Bright Finish Smooth surface finish with grindstone pattern R Stone Finish Surface finish with directional grind stone pattern M Matte Finish Dull surface finish Double Rolled R Stone Finish Surface finish with directional grindstone pattern

5. Chemical Treatment

Electro-plated tin plate is chemically or electrochemically treated after coating.

6. Oiling

Electro-plated tin plate is oiled on the coated surface. Remark: Tin plates that are oiled are CSO, DOS or DOS-A.

7. Sizes and Shapes

Thickness and Thickness Tolerance

Thickness If the nominal thickness of black plate is under 0.50mm, it should be the multiples of 0.01mm and for over 0.50mm, it should be the multiples of 0.05mm. Thickness Tolerance Thickness tolerance of tin plate and black plate is ±10% to the nominal thickness. Measurement area is limited to any place within the 10mm from the edge. For double cold-rolled products, thickness is measured within 6mm from the edge. The disparity between this value and nominal thickness is defined as the transverse thickness and the tolerance is 15%. With Tolerance Width tolerance should be within 0~+3mm to the specified size.

Length Tolerance

Length Tolerance of Black Plate and Tin Plate Length tolerance should fall within +5~0 mm to the specified size. It is preferable to stay within +3~0 mm. Length Tolerance of Coil and Black Plate Coil Length tolerance is applied to the nominal coil length and is subject to the specifications in the table below. However, it is not applied when trading by actual weight. Number of Coil in 1 Lot Length Tolerance % 1-4 ±3.5 5-99 ±3.0 100 and over ±1.0 Width of Rolling In case code is necessary for width of rolling, "W" is added to the rolling width size of the sheets and black plate sheets. (e.g.:832W×860) Inner Diameter of Coil The standard for nominal inner diameter of coil and black plate coil should be 406mm,419mm and 508mm. Flatness Coil and black plate coil are placed on the flat sheet to measure the bow, center buckle, and edge wave. The measurement should not exceed 5mm and it is preferable to stay within 3mm. Off-Squaredness Off-squaredness of a sheet is the ratio of A to B, as shown in the picture. A is the deviation from the straight line drawn at a right angle to the other side of the sheet. B is the length of the perpendicular line. The ratio should not exceed 0.25%. Furthermore, it is preferable to fall within 0 to 0.15%. Off-squareness: A/B ×100(%) Camber The camber of coil and black plate coil should not exceed 1.5mm to any given 1000mm in length, as shown in the picture. <Off-Squaredness> <Camber>

8. WEIGHT

Weight and Handling : Theoretical weight of tin plate and black plate is used in principle. However, if purchaser and manufacturer agree to use the actual weight, it can be arranged as well. Calculation Method : The weight of tin plate and black plate is calculated using specified size according to the calculation method given in the table below. Calculating Procedure Calculation Method Rounding-Off of the Result Sheet and Black Plate Sheet Basic Weight(kg/mm,m2) 7.85 (thickness 1mm, area 1m2) - Unit Weight(kg/m2) Basic weight (kg/mm,m2)×Thickness (mm) Rounding -off to 4 significant figures 1Sheet Area(m2) Width (mm)×Length (mm)×10 Rounding-off to 4 significant figures 1Sheet Weight (g) Unit weight (g)×1sheet area(m2)×10 Rounding-off to the integral number of g Bundle Weight (kg) 1sheet weight(g)×Number of sheets in a bundle×10 Rounding-off to the integral number of kg Total Weight(kg) Aggregated gross weight of each bundle(g) Integer of kg Coil and Black Plate Coil Unit Weight(kg/m2) Unit weight of sheet and black plate (kg/m2)×Width (mm)×10 Rounding-off to 3 significant figures 1Coil Weight(kg) Unit weight (kg/m2)×Length(mm) round-off to integral number of kg Total Weight(kg) Aggregated gross weight of each coil and black plate coil(kg) Integer of kg Remark: Rounding off the numerical value shall be in accordance with JIS Z 8401(number rounding- off method).

9.Weight Tolerance

Weight tolerance of one lot is presented in percentage quotient where the difference between a theoretical weight obtained by given calculation method and an actual weight is divided by the theoretical weight. Weight of 1 Lot (ton) Tolerance % Remarks 2and over, under 20 ±5 The sheets of same classification, dimension and coating weight in identical contracts shall be deemed as one lot for calculation of theoretical weight. 20and over ±3

10. Appearance

Tin plate and black plate must have consistent thickness. The surface must be smooth and even, without any detrimental flaws, dents, wrinkles, rust, etc. For coil and black plate coil, there may be some welded parts and irregularity since there is no opportunity to remove such defects during manufacturing.

11. Steel Type

Steel type

Major steel types are MR, L, and D. For other steel types, consultations between buyer and manufacturer are necessary. Type Features MR It has few residual minor constituents and good corrosion resistance. It is the most commonly used type. L L steel has very few metalloids and residuum like Cu, Ni, Cr and Mo. It is suitable for making containers with high corrosion resistance. D D steel is AL killed steel and suitable for deep drawing or other works, which are liable to create Luder's pattern.