Are metal expansion anchor or plastic expansion anchor better?
The choice between metal and plastic expansion tubes depends primarily on load-bearing capacity, base material, environmental factors, and budget.
| Metal expansion anchor (carbon steel / stainless steel) | Plastic expansion tubes (nylon/PP, commonly known as “small yellow fish”) | |
|---|---|---|
| Load-bearing capacity: | Extremely high (approximately 245kg for M6 concrete), suitable for heavy loads | Relatively low, suitable for light loads (≤5kg) |
| Applicable substrates: | Rigid substrates such as concrete and solid brick walls | Soft/brittle substrates such as hollow bricks, gypsum board, and aerated concrete blocks |
| Environmental adaptability | Stainless steel is corrosion resistant; carbon steel is prone to rusting when damp. | Insulating and rust-free; prone to aging with prolonged exposure to sunlight/high temperatures. |
| Installation and Damage | High expansion force may crack the substrate; precise drilling is required. | Good elasticity minimizes damage to the substrate; simple installation. |
| Price | Relatively high (approximately 10–20 times that of plastic) | Extremely low, high cost-performance ratio |
| Lifespan | Long (metals are durable) | Shorter (plastics age easily) |
Advantages and Disadvantages of Metal Expansion Anchor
Advantages: High strength, strong load-bearing capacity, shear and tensile resistance, durable, and resistant to loosening over time.
Disadvantages: High price, carbon steel is prone to rust, and improper installation can easily crack walls.
Recommended Scenarios: Fixing air conditioner outdoor units, water heaters, heavy-duty wall cabinets, security grilles, steel structures; concrete/solid brick walls, long-term outdoor use, damp environments (stainless steel is recommended); installation of heavy objects weighing >5kg.
Advantages and Disadvantages of Plastic Expansion Tubes
Suitable for “light, soft, and economical” scenarios
Advantages: Inexpensive, insulating, rust-free, quick installation, minimal damage to walls.
Disadvantages: Low load-bearing capacity, prone to aging under high temperatures/sunlight exposure, and prone to loosening over time.
Recommended Scenarios: Curtain rods, decorative paintings, small lamps, towel racks, small shelves; soft/porous walls such as hollow bricks, plasterboard, and aerated concrete blocks; dry indoor spaces, temporary/light-load fixing.
