Plywood thickness—measured in millimeters (mm)—is a critical factor defining its structural strength, flexibility, and application. Standard thicknesses range from ultra-thin 0.2mm veneers to robust 25mm+ structural panels, each engineered for specific uses. Below, we break down the classifications by thickness, material, and function to help you select the ideal type.

Standard Thickness Categories

1. Thin Plywood (0.2mm–6mm)

• 0.2–0.4mm: Used as decorative veneers bonded to thicker substrates like MDF or particleboard for surfaces requiring intricate wood grains or patterns.

• 3–6mm: Flexible and lightweight, ideal for cabinet backing, crafts, and curved furniture components.

2. Medium Thickness (9mm–18mm)

• 9–12mm: The most versatile range. Suitable for wall paneling, subflooring, furniture (shelves, tables), and packaging. E2/E1 grades (≤30mg/100g formaldehyde) are common for indoor use.

• 15–18mm: High-load applications like workbenches, vanities, and structural sheathing. Often classified as BWP (Boiling Water Proof) for moisture-heavy areas like kitchens.

3. Thick Plywood (≥19mm)

• 19–25mm+: Designed for heavy-duty use: roofing, industrial flooring, and shipping containers. May integrate fire-resistant or termite-proof treatments (e.g., Greenply Gold Plywood).

Table: Common Applications by Thickness

Classification by Material & Function

Beyond thickness, plywood types vary by core material and specialty treatments:

• By Material

• Hardwood (Birch, Oak): High-density layers for furniture and flooring.

• Softwood (Pine, Fir): Lightweight; used in construction framing.

• Bamboo: Eco-friendly alternative with superior tensile strength.

• By Water Resistance (ISO 1096:2014 Standards):

• Type 1 (Exterior): Waterproof (e.g., phenolic birch laminate for bridges).

• Type 2 (Interior): Moisture-resistant but not submersible (e.g., bathrooms).

• Type 3 (Indoor): Limited damp exposure (e.g., furniture).

• Specialty Types

• Fire-Rated: Treated with retardants for commercial spaces.

• Flexi-Ply: Thin (3–5mm) with cross-grain layers for curved designs.

• Marine Grade: Tropical hardwoods + waterproof adhesives for boats.

Key Selection Factors

When choosing mm-graded plywood:

• Load Requirements: Thicker panels (≥18mm) handle dynamic loads (e.g., flooring).

• Moisture Exposure: Opt for BWP or Type 1 in wet areas.

• Formaldehyde Levels: E0 (≤0.5mg/100g) for bedrooms; E2 (≤30mg/100g) for non-living spaces.

• Surface Finish: UV-coated or melamine-overlaid boards resist scratches and fading.

Innovations & Sustainability

Modern plywood blends performance with eco-innovation:

• Recycled Content: Brands like MDF Recovery Ltd. use post-consumer wood fiber to reduce waste.

• Low-Emission Coatings: UV-cured and formaldehyde-scavenging finishes improve air quality.

• Hybrid Boards: Plywood-MDF composites offer stability (from plywood) and smoothness (from MDF) for premium finishes.

Conclusion: Matching Thickness to Purpose

From delicate 0.2mm veneers to rugged 25mm structural slabs, plywood’s mm-based diversity ensures a fit for every project. Prioritize:

• <6mm: Decorative or lightweight uses.

• 9–18mm: All-purpose furniture and construction.

• >18mm: Heavy-load or weather-exposed structures.

Pro Tip: Always verify compliance with international standards (e.g., ISO 1096, GB/T 9846) for safety and durability.