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Artificial Grass Pins – 4mm Heavy-Duty Galvanised U-Pins (100 Pack)
Designed for tougher installations, our 4mm galvanised artificial grass fixing pins provide extra strength and holding power for hard ground conditions and larger sub-base materials.
Each pack contains 100 heavy-duty U-pins, ideal for professional installs or areas where additional anchoring strength is required.
Why Choose 4mm Artificial Grass Pins?
Our 4mm pins are thicker and stronger than standard 3mm and 3.6mm pins, making them ideal for:
- Hard compacted ground
- 40mm MOT Type 1 sub-base
- Hardcore foundations
- Limestone sub-base
- Commercial or high-traffic areas
- Areas prone to movement
If you’re installing onto a firm, dense or coarse sub-base, 4mm pins offer superior grip and long-term stability.
4mm vs 3.6mm & 3mm – What’s the Difference?
- 3mm pins are ideal for softer, finer ground such as soil, sand or granite dust and are typically used where no 20–40mm MOT sub-base is installed.
- 3.6mm pins are ideal for standard domestic installations with a typical 20mm compacted MOT Type 1 sub-base.
- 4mm pins are recommended for harder ground or where maximum holding strength is needed.
For most residential installations, 3.6mm pins are sufficient. However, if your ground is particularly firm or you want maximum long-term stability, upgrading to 4mm is recommended. If in doubt, 4mm provides additional durability and peace of mind.
Product Specification
- Diameter: 4mm (heavy-duty)
- Type: U-Pin / Fixing Pin
- Material: Galvanised steel (anti-rust coated)
- Pack Size: 100 pins
- Suitable for: Domestic & commercial installations
- Designed for: Hard ground & larger sub-base
Manufactured from corrosion-resistant galvanised steel for long-term outdoor performance in UK weather.
Where to Use 4mm U-Pins?
Perimeter Securing
Use pins around the perimeter of your lawn if you are not installing timber or composite edging. Install approximately every 200mm (20cm) for secure fixing.
Internal Stabilising
Add one pin per square metre across the main lawn area to prevent shifting or movement over time.
Joint Reinforcement
When joining two pieces of artificial grass, secure with joint tape and adhesive, then reinforce with pins every 200mm. Install using a “zip effect” to bind both sides together evenly.
How Many 4mm Pins Do I Need?
As a general installation guide:
- Perimeter: 1 pin every 200mm
- Internal area: 1 pin per m²
- Joints: 1 pin every 200mm along seam
A 100-pack typically secures approximately 30–40m² depending on layout and edging type.
For larger areas or commercial projects, multiple packs may be required.
Are 4mm Pins Harder to Install?
Due to their increased thickness, 4mm pins require slightly more force to install. A hammer is recommended.
Will These Rust?
No. Our pins are galvanised to resist corrosion and are designed for long-term outdoor use in British weather conditions.
Installation Tips
- Lay the artificial grass in position and secure one end first.
- Tension and stretch the artificial grass using a carpet kicker for a tight, professional finish.
- Work around the perimeter at 200mm intervals. Take care not to trap grass fibres when driving the pins into the ground.
- Add internal stabilising pins.
- Brush fibres upright to conceal pin heads
When installed correctly, the pins remain discreet and hidden within the grass pile.
Complete Your Installation
Where required, for best results, customers also purchase:
- Artificial Grass Joint Tape
- Artificial Grass Adhesive
- Weed Membrane
- Composite Edging Systems
- Shockpad Underlay
Ensure you have all installation materials before starting your project.
Can I use 4mm pins on standard sub-base?
Yes. While 4mm pins are designed for harder ground conditions, they can also be used on standard domestic installations where additional holding strength is preferred.
Why Buy From Artificial Super Grass?
- 1400+ Verified 5-Star Reviews
- Family-Run UK Business
- Nationwide Delivery
- Free Sample Service
- Trusted Artificial Grass Network Installers