Plat Kapal, Stainless, Tembaga, Kuningan Hingga Plat BKI

Complete Guide to Steel Plates: Types, Sizes, Stainless, Ship Plate, BKI Plate, Copper, Brass, Weight Formula & Industrial Uses

Steel plates are one of the most important materials in construction, manufacturing, fabrication, shipbuilding, and industrial engineering. From high-rise buildings and bridges to tanks, ships, factories, and decorative interiors, steel plates are used almost everywhere.

However, many buyers, contractors, and even beginners still do not fully understand the differences between:

• Standard steel plates

• Shipbuilding plates

• Stainless steel plates

• BKI certified plates

• Copper plates

• Brass plates

• Chinese imported steel plates

• Local Indonesian steel plates

This article explains everything in a simple and natural way, including:

• Types of steel plates

• Standard plate sizes

• Uses and applications

• Factory brands and manufacturers

• Imported vs local materials

• Weight calculation formulas

• Plate specifications for industrial projects

This guide is suitable for:

• Contractors

• Engineers

• Fabricators

• Shipyard companies

• Steel traders

• Industrial workshops

• Students

• Manufacturing companies

What Is a Steel Plate?

A steel plate is a flat sheet of metal manufactured in various thicknesses, widths, and lengths. Steel plates are commonly used for:

• Building structures

• Bridges

• Tanks

• Ships

• Heavy equipment

• Machine fabrication

• Roofing support

• Industrial flooring

• Decorative panels

• Pressure vessels

Steel plates are available in different materials such as:

• Carbon steel

• Stainless steel

• Galvanized steel

• Copper

• Brass

• Aluminum

• Marine steel

• Abrasion resistant steel

Standard Steel Plate Sizes in Indonesia

1. Standard 4x8 Feet Steel Plate

The most common plate size in Indonesia.

Standard dimensions:

4\text{ feet} \times 8\text{ feet} \approx 1.2\text{ m} \times 2.4\text{ m}

Actual size:

• Width: 1220 mm

• Length: 2440 mm

Common names:

• 4x8 plate

• Mild steel plate

• Black steel plate

Available thickness:

• 0.8 mm

• 1.2 mm

• 1.5 mm

• 2 mm

• 3 mm

• 4 mm

• 5 mm

• 6 mm

• 8 mm

• 10 mm

• 12 mm

• 16 mm

• 20 mm

Main applications:

• Steel fabrication

• Gates and fences

• Tanks

• Industrial machinery

• Canopies

• Workshop projects

• Structural support

2. Shipbuilding Plate (5x20 Feet)

Ship plates are designed for heavy-duty marine and industrial projects.

Size:

5\text{ feet} \times 20\text{ feet} \approx 1.5\text{ m} \times 6\text{ m}

Actual dimensions:

• 1524 mm x 6096 mm

Common thickness:

• 3 mm

• 4 mm

• 5 mm

• 6 mm

• 8 mm

• 10 mm

• 12 mm

• 16 mm

• 20 mm

• 25 mm

• 30 mm

Common uses:

• Ship hulls

• Barges

• Offshore structures

• Heavy tanks

• Dock construction

• Marine platforms

Advantages:

• Longer sheets reduce welding joints

• Stronger structural performance

• Better efficiency for large projects

3. 6x20 Feet Steel Plate

Large-size jumbo steel plate for heavy industrial projects.

Size:

6\text{ feet} \times 20\text{ feet} \approx 1.8\text{ m} \times 6\text{ m}

Actual dimensions:

• 1828 mm x 6096 mm

Usually used for:

• Shipbuilding industries

• Tank fabrication

• Pressure vessels

• Offshore construction

• Heavy engineering projects

Types of Steel Plates

1. Mild Steel Plate (Black Steel Plate)

This is the most common and affordable steel plate.

Characteristics:

• Dark gray or black surface

• Easy to weld

• Easy to cut and bend

• Economical price

Applications:

• Structural fabrication

• Machine bases

• Steel frames

• Tanks

• Workshop fabrication

Popular brands:

• Krakatau Steel

• Gunung Garuda

• Master Steel

• Chinese imported plates

Manufacturers:

• PT Krakatau Steel

• PT Gunung Raja Paksi

• PT Gunung Garuda

2. Shipbuilding Plate

Marine-grade steel plate specially designed for ships and offshore projects.

Features:

• Higher tensile strength

• Better corrosion resistance

• Heavy-duty performance

Popular grades:

• ASTM A36

• AH36

• DH36

• EH36

Common uses:

• Ship hulls

• Oil barges

• Offshore platforms

• Marine engineering

Certifications:

• BKI

• ABS

• LR

• DNV

• BV

3. BKI Steel Plate

BKI stands for:

Biro Klasifikasi Indonesia

BKI certified plates are approved for shipbuilding and marine applications.

Why BKI plates are important:

• Certified for marine use

• Tested according to shipbuilding standards

• Comes with mill certificates

• Required for many marine projects in Indonesia

Common uses:

• Cargo ships

• Tankers

• Fishing vessels

• Offshore structures

4. Stainless Steel Plate

Stainless steel is corrosion-resistant and widely used for hygienic and decorative applications.

Most popular grades:

• SS201

• SS304

• SS316

Differences:

Applications:

• Food industry

• Hospitals

• Kitchen equipment

• Pharmaceutical factories

• Decorative interiors

• Chemical plants

Surface finishes:

• Hairline (HL)

• Mirror

• 2B

• Matte finish

Popular brands:

• TISCO

• POSCO

• YUSCO

• BAOSTEEL

• Chinese imports

5. Copper Plate

Copper plates are widely used in electrical and decorative industries.

Main uses:

• Electrical grounding

• Decorative panels

• Mosque domes

• Industrial electrical systems

Advantages:

• Excellent electrical conductivity

• Corrosion resistant

• Premium appearance

6. Brass Plate

Brass is made from copper and zinc alloy.

Characteristics:

• Gold-like appearance

• Elegant finish

• Easy to form and machine

Common applications:

• Interior decoration

• Hotel ornaments

• Furniture accessories

• Luxury architectural details

Local Steel Plate vs Chinese Imported Steel Plate

The Indonesian market currently uses both local and imported steel plates.

Chinese imported plates are popular because:

• Lower prices

• Large stock availability

• More size variations

However, quality differences may exist.

Advantages of Local Steel Plates

Benefits:

• Stable quality

• Clear certification

• Suitable for government projects

• Better traceability

Local manufacturers:

• Krakatau Steel

• Gunung Garuda

• Gunung Raja Paksi

• Krakatau Posco

Advantages of Chinese Imported Steel Plates

Benefits:

• Competitive pricing

• Easier availability

• Wide thickness selection

Possible disadvantages:

• Some products may have under tolerance thickness

• Quality consistency varies by supplier

Steel Plate Weight Calculation Formula

The standard steel plate weight formula is:

\text{Weight} = t \times W \times L \times 7.85

Where:

• t = thickness (mm)

• W = width (meter)

• L = length (meter)

• 7.85 = steel density constant

Example: Weight of 4x8 Steel Plate

Example:

• Thickness: 3 mm

• Size: 1.2 m x 2.4 m

Calculation:

3 \times 1.2 \times 2.4 \times 7.85 \approx 67.8\text{ kg}

Approximate weight:

68 kg per sheet

Example: Weight of Ship Plate 5x20 Feet

Example:

• Thickness: 10 mm

• Size: 1.5 m x 6 m

Calculation:

10 \times 1.5 \times 6 \times 7.85 \approx 706.5\text{ kg}

Approximate weight:

706 kg

Surface Types of Steel Plates

1. Plain Plate

Smooth flat surface.

2. Checkered Plate (Bordes Plate)

Anti-slip patterned surface.

3. Perforated Plate

Steel plate with holes.

4. Expanded Metal

Slit and stretched metal mesh plate.

How to Choose the Right Steel Plate

For general construction:

Use mild steel plates.

For shipbuilding:

Use BKI certified marine plates.

For anti-rust applications:

Use SS304 or SS316 stainless steel.

For decorative projects:

Use brass or hairline stainless steel.

For electrical grounding:

Use copper plates.

Why Steel Plate Prices Change Frequently

Steel plate prices depend on:

• Thickness

• Material grade

• Brand

• Certification

• Import or local production

• Global steel prices

• Currency exchange rates

• Shipping costs

Most Popular Steel Plate Brands in Indonesia

Popular steel brands include:

• Krakatau Steel

• Gunung Garuda

• Gunung Raja Paksi

• Master Steel

• Krakatau Posco

• BAOSTEEL

• POSCO

• TISCO

• YUSCO

Conclusion

Steel plates are essential materials for construction, shipbuilding, fabrication, and industrial engineering. Each type of plate has different functions, strengths, and specifications.

From standard 4x8 mild steel plates to 5x20 shipbuilding plates, stainless steel, BKI certified marine plates, copper plates, and brass plates, choosing the right material is very important for project safety, durability, and cost efficiency.

Before purchasing steel plates, always consider:

• Plate size

• Thickness

• Material type

• Weight calculation

• Brand reputation

• Certification requirements

• Local vs imported quality

Choosing the correct steel plate will improve:

• Structural safety

• Project durability

• Fabrication efficiency

• Long-term performance

For industrial projects, marine construction, factory fabrication, or custom steel requirements, always work with a trusted steel distributor that provides original materials, proper certifications, accurate thickness, and professional technical support.