Electro-galvanized Steel Sheet (Silver Top)

We provide a wide lineup of sheet thicknesses from 25 μm to 1.2 mm with functionality such as beautiful surface finishes, scratch-resistance, workability, paintability, solderability and conductivity.

Surface-treated steel sheet is used for many different purposes. Of the various types electrogalvanized steel sheet has the highest market share. Galvanized steel sheet can be divided into hot-dip galvanized steel sheet and electrogalvanized steel sheet (JIS G3313 EG). Toyo Kohan's "Silver Top" has been the leader in the electrogalvanized steel sheet field. As Silver Top has many superior properties that are not available in other products, ever since production started in 1967 it has been used for a wide range of uses and has an excellent reputation.
For example, it is available in a beautiful golden color that changes the image of ordinary galvanized steel sheet, so that it is used for various design purposes such as different types of cases, covers and panels. In addition, our advanced rolling technology makes it possible for us to produce ultra-thin 25 μm sheets (SF) which is unprecedented in galvanized steel sheets. This is helping our customers to reduce costs by replacing copper foil, albata and phosphor bronze foil. Scratch-resistant steel sheet makes stamping of small parts possible and we have helped customers improve their yields by supplying steel sheet with mechanical properties suitable for machining. Due to these factors, Silver Top has been used in many different fields for years.
The increased price of nickel in recent years has led to the increase in the price of stainless steel. Therefore, we have developed "High-strength Silver Top" to replace stainless steel. High-strength Silver Top is much stronger than regular cold-rolled steel sheet, has added elasticity, can be drawn and has various types of galvanizing. It is being used as a new material in electrical and electronic components to reduce costs.

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Feature

Features 1 Corrosion resistance

  • Protects steel sheet from corrosion through the self-sacrificing corrosion resistance feature unique to galvanization.
  • Corrosion resistance and paint adhesion are further improved with a composite Zn-Co-Mo galvanization.

Features 2 Diversity

  • A diverse product lineup is available that features different functions for different uses.

Features 3 Ultra-thin sheeting available

  • Rolling technology makes production of sheets from 25 μm (steel foil) possible.
Substrate Product name Specifications Coating structure Features
SPCC, SPCD, high-strength substrate Unpainted Silver Top HE-71
(Conductivity emphasized)
HE-72
(Corrosion-resistance emphasized)
HE-73
(Wear-resistance emphasized)
HE-71, 72
  • Special organic layer
  • Chemical conversion treatment layer
  • Zn-Co-Mo
  • Base steel
HE-73
  • Li-Si
  • Zn-Co-Mo
  • Base steel
Ease of design
  • A beautiful, smooth golden finish makes it possible to eliminate later painting processes (reduced work processes).
  • Reduces waste paint and other waste materials produced from painting processes.
Scratch-resistant and smooth
  • Low surface friction coefficient, so that die biting (scratches and peeling of galvanization) is rare.
  • Smooth flow is assured in paper feed and other drive mechanisms.
Fingerprint resistant
  • Fingerprints of assembly line workers and users to not show up as much.
Easy to weld
  • Can be used for grounding for various types of joining, such as spot welding.
SPCC, SPCD, high-strength substrate Silver Top for painting TE-90
(Gloss plating)
TE-91
(Matte plating)
  • Phosphoric acid treatment
  • Zn-Co-Mo
  • Base steel
Paint adhesion
  • A precise phosphoric acid layer assures that various types of rubber lining and paints have superior adhesion.
SPCC, SPCD, high-strength substrate Silver Top for soldering ZE-36
(Corrosion-resistance emphasized)
ZE-38
(Ease of soldering emphasized)
  • Special organic layer
  • Zn
  • Steel sheet
Solderability
  • Soldering on galvanized steel sheet is possible.
  • Solves the red corrosion problem that develops for tin plate and tin plated steel sheet in the distribution process.
Whisker-resistance
  • Does not include any tin, so that it is more difficult for whiskers to develop.
Surface conductivity
  • The contact resistance of the surface is low, so that this material can be grounded even with surface contact.
Shielding of electromagnetic waves
  • Cuts the entry and leakage of electromagnetic waves that can cause noise.
SPCC, SPCD, high-strength substrate Black Silver Top for soldering ZEB26
  • Black organic layer
  • Zn
  • Steel sheet
Heat dissipation
  • Has good surface heat emission to reduce the internal temperature of electrical and electronic devices.
Solderability
  • Soldering on galvanized steel sheet is possible.
  • Solves the red corrosion problem that develops for tin plate and tin plated steel sheet in the distribution process.
Surface conductivity
  • The contact resistance of the surface is low, so that this material can be grounded even with surface contact.
Shielding of electromagnetic waves
  • Cuts the entry and leakage of electromagnetic waves that can cause noise.
SPCC, SPCD, high-strength substrate Black Silver Top BEP22
(Corrosion-resistance emphasized)
BEX28
(Conductivity emphasized)
BEP22
  • Special organic layer
  • Phosphoric acid treatment
  • Zn-Co-Mo
  • Steel sheet
BEX28
  • Special organic layer
  • Chemical conversion treatment layer
  • Zn-Co-Mo
  • Steel sheet
Ease of design (black exterior)
  • This is a black steel sheet that helps reduce costs by switching from steel sheet that is colored black.
Heat dissipation
  • Has good surface heat emission to reduce the internal temperature of electrical and electronic devices.
Surface conductivity
  • The contact resistance of the surface is low, so that this material can be grounded even with surface contact.
Shielding of electromagnetic waves
  • Cuts the entry and leakage of electromagnetic waves that can cause noise.
SPCC, SPCD, high-strength substrate SF
Chromate
  • Chromate treatment
  • Zn
  • Steel sheet
Ecological type
  • Chemical conversion treatment layer
  • Zn
  • Steel sheet
  • Can be made lighter and thinner while maintaining the strength of steel and magnetic attraction.
  • Holes opened by lack of piercing strength in aluminum foil, etc.
Uses

From standard industry products to leading-edge products, this product is used in the lives of people around the world.

Unpainted Silver Top

Photocopiers (paper feeders, etc.)

Precision machinery (bearing sealing units, etc.)

PC equipment (CD/DVD drive tray parts, pick-up parts, etc.)

Silver Top for painting

Automobile parts (cylinder head gaskets)

Electric wire and cable parts (cable armor, etc.)

Automobile parts (bearing rubber seals)

Silver Top for soldering

Automobile A/V equipment (internal parts)

Electrical and electronic parts (tuner cases, heat sinks)

LCD bezel parts

Various game equipment (power supply parts, etc.)

Cell phone parts

A/V equipment (digital camera parts)

Black Silver Top

Automobile A/V equipment (car audio parts, etc.)

Automobile A/V equipment (slide rails)

SF

Construction material (flexible ducts)

PC HDD vibration damping material

Production Process

In order to assure that the properties meet the requirements, Silver Top is made with the newest equipment and technology under strict quality controls.

Manufacturing Process

Available Sizes
Specifications Producible sizes (mm) Custom sizes (mm)
Sheet thickness Width Sheet thickness Width
MIN. MAX. MIN. MAX.
Unpainted Silver Top and Silver Top for painting - - - 0.11 500 800
- 500 914 0.12 to 0.149 500 1000
0.15 to 0.199 500 950 0.15 to 0.199 - 1000
0.20 to 0.59 500 1000 0.60 to 0.80 - 1000
0.60 to 1.20 500 950 0.81 to 1.00 - 950
- 500 914 1.21 to 1.60 500 650
Silver Top for soldering - - - 0.11 to 0.149 500 800
0.15 to 0.199 500 914 0.15 to 0.199 - 1000
0.20 to 0.60 500 1219 - - -
0.61 to 1.00 500 950 0.61 to 1.20 - 1000
1.01 to 1.20 500 914 - - -
Black Silver Top 0.15 to 1.20 500 914 0.15 to 0.80 - 1000
- - - 0.81 to 1.00 - 950
- - - 1.21 to 1.60 500 650
SF-Z Hard - - - 25 to 49µm 550 810
50 to 100µm 550 930 50 to 100µm 550 or less -
Soft 80 to 100µm 550 700 80 to 100µm 550 or less -
High-strength Silver Top (for machining) HS55F - - - 0.11 to 0.149 500 900
0.15 to 0.59 500 860 0.15 to 0.59 - 900
HS53F 0.60 to 0.80 500 800 0.81 to 1.20 500 800
High-strength Silver Top (for springs) HS85S - - - 0.11 to 0.149 500 820
0.15 to 0.59 500 860 0.15 to 0.59 - 900
- - - 0.61 to 0.70 500 860
HS10S 0.15 to 0.49 500 820 - - -
HS12S
Unpainted Silver Top and Silver Top for painting
fig: Unpainted Silver Top and Silver Top for painting
Black Silver Top
fig: Black Silver Top
Silver Top for soldering
fig: Silver Top for soldering
SF-Z
fig: SF-Z
High-strength Silver Top (for machining)
fig: High-strength Silver Top (for machining)
High-strength Silver Top (for springs)
fig: High-strength Silver Top (for springs)
Standard Products

Silver Top and Silver Top-ECO are manufactured under strict quality controls based on standards comparable to JIS G 3313.

Types of substrates and temper categories

Equivalent JIS standard Toyo Kohan Standard Mechanical properties (reference) Remarks
Tensile strength Extension Hardness
Type Temper category Temper symbol Temper symbol (N/mm²) (%) HR-30T
SPCC Standard S SN,SO,SE 270 or higher 25 or higher 58 or lower  
1/8 hardness 8 SUS 290 to 410 25 or higher 48 to 62  
1/4 hardness 4 SU4,SU5 370 to 490 10 or higher 58 to 68  
1/2 hardness 2 2 440 to 590 - 67 to 74  
Hard 1 1 550 or higher - 71 or higher  
SPCD Standard S SD,SD-CA 270 or higher 28 or higher 58 or lower  
  HS53F 420 to 550 20 to 35 61 to 71 High-strength steel sheet
HS55F 520 to 650 15 to 35 65 to 75
HS85S 780 to 950 5 to 23 75 to 83
HS10S 850 to 1100 3 to 20 78 to 85
HS12S 1100 to 1300 3 to 20 82 to 90

Galvanized Coverage (Per Side)

Nominal Coverage (g/m²) Minimum Coverage (g/m²) Comparable Plated Thickness (µm)
3 2.5 0.4
5 4.25 0.7
10 8.5 1.4
15 12.75 2.1
20 17 2.8

Reference: Comparable JIS Codes

Type Codes and Applicable Display Thicknesses (Using Cold Rolled Substrates)

Code Types Applicable Display Thickness (mm) Cold Rolled Substrate Type Codes Used Uses
SECC More than 0.4, Less than 3.2 SPCC General Purpose
SECD SPCD For Ties

* Compatible display thickness from 25 µm to 1.6 mm.

Chemical Process Types and Codes

Chemical Process Types Code
Chromate Process C
Phosphate Process P
Chromate Free Process NC
Chromate Free Phosphate Process NP
Non Processed M

* Compatible chemical processes are NC, NP and M.

Lubrication Types and Codes

Lubrication Types Code
Lubrication O
Non Lubrication X

Galvanized Coverage Label Codes

alvanized Coverage Label Codes Minimum galvanized coverage (g/m²) Standard galvanized coverage (g/m²)
ES - -
EB/EB 2.5 3
E8/E8 8.5 10
E16/E16 17 20
E24/E24 25.5 30
E32/E32 34 40
E40/E40 42.5 50

* The table above is for uniform thickness plating. * Compatible standard galvanized coverage is 5 to 30 g/m² for each 5 g/m².

List of Compatible JIS Code Comparable Products

Comparable JIS Codes Comparable Product Specification Codes
SECC-NC HE-71, HE-72, HE-73, ZE-36, ZE-38, ZEB26, BEP22, BEX28
SECC-NP TE-90, TE-91
SECC-M Non Processed Silver Top
SECD-NC HE-71, HE-72, HE-73, ZE-36, ZE-38, ZEB26, BEP22, BEX28
SECD-NP TE-90, TE-91
SECD-M Non Processed Silver Top

* No JIS Code comparable products containing the following hexavalent chrome are manufactured because the Silver Top series is completely chrome free. (SECC-C, SECC-P, SECD-C, SECD-P)

Product Family

We can provide a wide variety of functions that exceed the expectations of electrogalvanized steel sheet.

Unpainted Silver Top

  • Features such as a beautiful metallic appearance, high corrosion resistance, wear resistance, low paper friction, scratch resistance and fingerprint resistance, have led to an excellent reputation for this unpainted galvanized steel sheet for many years.

Silver Top for painting

  • This product has superior paint adhesion and a high grade paint finish that can only be achieved with electroplating. This has led to an excellent reputation for this product ever since it was put on sale because of the combination of these factors together with our unique ability to make 0.11 thickness sheets and the highly workable substrates we use.

Silver Top for soldering

  • This product has a history of over ten years as a steel sheet for lead-free soldering. This product has the properties required for electronic parts, such as good solder adhesion with lead-free solder and deactivated flux, whisker resistance, and a high shielding ability together with high surface conductivity.

Black Silver Top

  • Made with our original production methods, this product has the necessary properties to replace painted steel sheet, such as a greatly improved black appearance, the same properties as our unpainted Silver Top and heat dissipation properties only possible with black steel sheet.

Steel Foil (SF)

  • This is an ultra-thin galvanized steel sheet from 25 to 100 µm thickness that is made with our ultra-thin rolling technology that is represented by our shadow mask material. Our regular Silver Top can be used for thicknesses of 110 µm and higher.

Composite Galvanized Products

Type Unpainted Silver Top
Coating specs HE-71 HE-72 HE-73
Coating composition
  • Special organic coating
  • Chemical conversion coating
  • Zn-Co-Mo
  • Steel sheet
  • Special organic coating
  • Chemical conversion coating
  • Zn-Co-Mo
  • Steel sheet
  • Li-Si
  • Zn-Co-Mo
  • Steel sheet
Functions Corrosion resistance
Conductivity
Smooth surface
Scratch resistance
Fingerprint resistance
Corrosion resistance
Smooth surface
Scratch resistance
Fingerprint resistance
Corrosion resistance
Wear resistance
Smooth surface
Scratch resistance
Fingerprint resistance
Zn quantity 3 to 20 g/m² 3 to 20 g/m² 3 to 20g/m²
Sheet thickness range 0.15 to 1.2 mm 0.15 to 1.2 mm 0.15 to 1.2 mm
Type For painting Silver Top Black Silver Top
Coating specs TE-90 TE-91 BEP22 BEX28
Coating composition
  • Phosphate processing
  • Zn-Co-Mo
  • Steel sheet
  • Phosphate processing
  • Zn-Co-Mo
  • Steel sheet
  • Black organic coating
  • Phosphate processing
  • Zn-Co-Mo
  • Steel sheet
  • Black organic coating
  • Chemical conversion coating
  • Zn-Co-Mo
  • Steel sheet
Functions Paint adhesion Paint adhesion
(Heat resistance)
Corrosion resistance
Smooth surface
Fingerprint resistance
Heat dissipation
Conductivity
Smooth surface
Fingerprint resistance
Heat dissipation
Zn quantity 3 to 20 g/m² 3 to 20g/m² 3 to 20 g/m² 3 to 20 g/m²
Sheet thickness range 0.15 to 1.2 mm 0.15 to 1.2 mm 0.2 to 1.6 mm 0.2 to 1.6 mm
* Consult for thicknesses from 0.15 to 0.19 * Consult for thicknesses from 0.15 to 0.19

Pure Galvanization

Type Silver Top for soldering Black soldering Silver Top SF Silver Top
Coating specs ZE-36 ZE-38 ZEB26 SF-Z SF-42
Ecological type Ecological type Ecological type Chromate Ecological type
Coating composition
  • Special organic coating
  • Zn
  • Steel sheet
  • Special organic coating
  • Zn
  • Steel sheet
  • Black organic coating
  • Zn
  • Steel sheet
  • Chromate coating
  • Zn
  • Steel sheet
  • Chemical conversion coating
  • Zn
  • Steel sheet
Functions Solderability Conductivity Solderability Conductivity Conductivity Solderability Heat dissipation Corrosion resistance Corrosion resistance
Zn quantity 3 to 20 g/m² 3 to 20 g/m² 3 to 20 g/m² 3 to 20 g/m² 3 to 20 g/m²
Sheet thickness range 0.15 to 1.2 mm 0.15 to 1.2 mm 0.15 to 1.2 mm 0.05 to 0.10 mm 0.05 to 0.10 mm
* Consult for thicknesses from 0.11 to 0.14 * Consult for thicknesses from 0.11 to 0.14 * Consult for thicknesses from 0.025 to 0.049 mm * Consult for thicknesses from 0.025 to 0.049 mm