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What is JIS G3303
JIS G3303 is Japanese Industrial Standard has been prepared based on ISO 11949 : 1995 and ISO 11951 : 1995, with some modifications of the technical contents.
The Standard JIS G3303 specifies requirements for tinplates and blackplates that are intended
mainly for beverage can or food can.
NOTE: The International Standards corresponding to this Standard and the
symbol of degree of correspondence are as follows.
ISO 11949: 1995 Cold-reduced tinmill products — Electrolytic tinplate
ISO 11951: 1995 Cold-reduced tinmill products — Blackplate (overall evaluation: MOD)
JIS G3303 Equivalent of Electrolytic Tinplate Sheet
Chinese standard: GBT 2520
European standard: EN 10203
American standard: ASTM A623M
Classification and Letter Symbol Of Tinplate And Blackplate
| Classification | Symbol of JIS G3303 |
| Blackplate | SPB |
| Electrolytic tinplate | SPTE |
| Hot-dipped tinplate | SPTH |
JIS G3303 Typical Steel Type for Black Plate
| Type of steel | Remark |
| MR | It contains few residual minor constituents and has a good corrosion resistance so that it is widely used for such applications as containers. |
| L | It contains particularly few residual minor constituents such as Cu, Ni, Cr, Mo, so that it is suitable for the materials of containers required improved corrosion resistance. |
| D | It is aluminium killed steel, so that it is suitable for the applications which bear deep drawing or other working that is liable to produce Luder’s lines pattern. |
Tin coating Mass of JIS G3303
Tin coating mass and method of expressing tin coating mass. The minimum average coating mass shall be specified for tinplates and black plates with the designation of tin coating mass of l g/M2 or more on one surface. The minimum average coating mass for electrolytic tinplate shall be based on the coating mass on one surface.
Designation of standard tin coating mass and its minimum average coating mass
| Letter symbol of classification | STPE | STPH | |
| Type of coating | Equally coated | Differentially coated | Equally coated |
| Designation of coating weight (g/m2) | 2.8/2.8 | 5.6/2.8 | 12.3/12.3 |
| 5.6/5.6 | 8.4/2.8 | 14.0/14.0 | |
| 8.4/8.4 | 8.4/5.6 | 15.1/15.1 | |
| 11.2/11.2 | 11.2/2.8 | 16.8/16.8 | |
| 11.2/5.6 | |||
| 11.2/8.4 | |||
| Nominal coating weight (g/m2) | 2.8/2.8 | 5.6/2.8 | 12.3/12.3 |
| 5.6/5.6 | 8.4/2.8 | 14.0/14.0 | |
| 8.4/8.4 | 8.4/5.6 | 15.1/15.1 | |
| 11.2/11.2 | 11.2/2.8 | 16.8/16.8 | |
| 11.2/5.6 | |||
| 11.2/8.4 | |||
| Minimum average coating weight (g/m2) | 2.45/2.45 | 5.05/2.45 | 19.7 |
| 5.05/5.05 | 7.55/2.45 | 22.4 | |
| 7.55/7.55 | 7.55/5.05 | 24.2 | |
| 10.1/10.1 | 10.1/2.45 | 26.9 | |
| 10.1/5.05 | |||
| 10.1/7.55 | |||
| Forner designation of coating weight (reference only) | #25 | #50/25 | #110 |
| #50 | #75/25 | #125 | |
| #75 | #75/50 | #135 | |
| #100 | #100/25 | #150 | |
| #100/50 | |||
| #100/75 | |||
JIS G3303 Designation System Of Differential Coating
Product marking to indicate different tin coating masses between two surfaces When either the lightly or heavily coated surface of differentially coatedtinplate is used for marking, the choice of the surface to be marked and the marking method shall be subjected to the agreement between the purchaser and the supplier and shall be clearly stated in the contract of order.
Method of designating differential coating
| Letter Symbol | Marking Method | Example of Designation |
| D | It shall be marked a continuous line about up to 2 mm width on the lighter coated surface near one of the trimmed side edges | 5.6/2.8D |
| A | If the marking is made on the lighter coated surface, it shall be drawn with geometrical pattern about 1mm width line. | 5.6A/11.2 |
| If the marking is made on the heavier coated surface, it shall be drawn continuous parallel lines about 1mm width. | 5.6/11.2A |
Temper Grade of JIS G3303
Temper grades for single cold-reduced tinplate and black plate shall be expressed in Rockwell superficial hardness (HR30T).
Temper Designation Of Single Cold-Reduced Product
| Temper Designation | Traget, Rockwell hardness HR30T |
| 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 |
| T-6 | 70+3 |
Temper grades for double cold-reduced tinplate and black plate shall be expressed in Rockwell superficial hardness (HR30T).
Temper Designation Of Double Cold-Reduced Product
| Temper Designation | Target, Rockwell Hardness | Target, proof stress (information only) parallel to rolling direction |
| HR30T | N/mm2 | |
| DR-8 | 73 | 550 |
| DR-9 | 76 | 620 |
| DR-9M | 77 | 660 |
| DR-10 | 80 | 690 |
JIS G3303 Surface Treatment
Classification of surface finishes for electrolytic tinplate
| Commodity | Letter Symbol | Classification | Specific Feature |
| Single cold-reduced products | B | Bright finish | A luster surface provided by a flow-brightened tin coating on a smoothly grindstone-finished steel base. |
| R | Stone finish | A luster surface provided by a flow-brightened tin coating on a steel base characterized by a directional grindstone-pattern. | |
| S | Silver finish | A luster surface provided by a flow-brightened tin coating on a coarse dull finished steel base. |
Surface Finish Classification Of Blackplate
| Single cold-reduced products | B | Bright finish | A smooth surface finish with a fine grindstone-pattern |
| R | Stone finish | A surface finish with a directional grindstone-pattern | |
| M | Matte finish | A dull surface finish | |
| Double cold-reduced products | R | Stone finish | A surface finish with a directional grindstone-pattern |
Dimensions Tolerances
Thickness Tolerances
Thickness tolerances for tinplate and black plate shall be + 10 % of the nominal thickness. Usually we can control the thickness tolerance according to the customer’s requirements.
Width Tolerances
Width tolerances shall be 3mm of the specified width.
Length Tolerances
Length tolerances for sheet and black plate sheet shall be 5 mm of the specified length. However, the tolerances should fall within 3 mm.
| Number of coils of one lot | Length tolerance % |
| 1 to 4 | 3.5 |
| 5 to 99 | 3 |
| 100 and over | 1 |
The above is a display of the main parameters in the JIS G3303 production standard. I hope it can help you better understand Tinplate. If you are looking for a Tinplate supplier, we hope you can contact us to give you a quote. If you need to find other suppliers, we are happy to help you.
