This D400 circular manhole cover assembly features an eight‑sided (octagonal) ductile‑iron frame with a locked cover, engineered to withstand a 400 kN (40 tonne) test load for carriageways, highways, and other heavy‑traffic areas. Crafted from GGG500/7 grade nodular iron per EN 1563/ISO 1083, it delivers high tensile strength (≥ 500 MPa) and exceptional impact resistance under repeated wheel loads. Precision machining and a three‑point suspension ensure a flush, non‑rock fit, while the integrated locking system secures the cover against unauthorized access and enhances site safety. With a 600 mm clear opening (cover Ø 625 mm) housed in an octagonal frame of Ø 820 × 100 mm, and weighing approx. 46 kg, this assembly balances robustness with manageable handling during installation and maintenance. A standard 30 µm bitumen coating (optional epoxy finish) protects against corrosion, and third‑party certification (BSI Kitemark, ISO 9001, SGS, BV) guarantees consistent quality and regulatory compliance.
Material & Construction
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Ductile Iron Grade
Manufactured from GGG500/7 nodular (ductile) iron per EN 1563 / ISO 1083, providing a minimum tensile strength of 500 MPa and proof stress of 320 MPa for outstanding durability under cyclic loading. -
Octagonal Frame
Eight‑sided frame geometry optimizes load distribution into surrounding pavement and provides clear reference points for alignment during installation. -
Locked Cover
Integrated locking mechanism prevents unauthorized opening and enhances security, with positive engagement even under vibration from passing traffic. -
Suspension System
Three‑point suspension ensures non‑rock performance and facilitates straightforward lift‑out for maintenance.
Technical Specifications
| Specification | Details |
|---|---|
| Clear Opening | Ø 600 mm |
| Cover Diameter | Ø 625 mm |
| Frame Outer Diameter | Ø 820 × 100 mm (Depth) |
| Load Class | D400 (400 kN / 40 t) |
| Assembly Weight | Approx. 46 kg |
| Material Standard | EN 1563 / ISO 1083 GGG500/7 |
| Coating | 30 µm bitumen (standard); epoxy optional |
Quality & Compliance
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Standards
Engineered and load‑tested to BS EN 124:2015 (Group 4 / D400) for vehicular access covers and gratings. -
Certification
Accredited with the BSI Kitemark, ISO 9001 quality management, SGS and Bureau Veritas audits for batch traceability and regulatory conformity. -
Corrosion Resistance
Black bitumen coating meets CD 534 requirements; optional epoxy finish available for coastal or chemically aggressive environments.
Applications & Benefits
This locked OCTO frame assembly is ideal for:
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High‑Traffic Roadways: Main roads, highways, and industrial estates requiring 40 t load capacity.
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Secure Access Points: Utility vaults, communication chambers, and critical infrastructure that demand tamper‑resistant covers.
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Efficient Maintenance: Three‑point suspension and manageable leaf weights simplify on‑site removal and replacement, reducing traffic disruption.
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Long‑Term Durability: Ductile iron and protective coatings minimize life‑cycle costs through extended service intervals.
| Family: | Municipal |
| Packaging Qty: | 10 |
| Product Type: | Access Covers |
| Product Ranges: | MAESTRO RANGE |
| Certified Class: | D400 |
| Standards: | EN124 |
| Surface Finish: | Anti-slip surface |
| Clear Opening: | 600 mm |
| Flange Outer Diameter: | 850 mm |
| Frame Height: | 100 mm |
| Weight: | 71 kg |
| Mass Per Unit Area: | 150 kg |
| Watertight: | No |
| Cover/Grating Shape: | Round |
| Cover Diameter: | 668 mm |
| Cover Security Block Angle: | 90 |
| Hinged: | Yes |
| Hinge Type: | B PK |
| Opening Direction: | Vertical |
| Gasket Installed: | Yes |
| Frame Style: | Monoblock as Cast |
| Frame Shape on Vertical Section: | Flat |
| Frame Surface Protection By: | Water-Based Paint |
| Nb Anchoring Hole: | 4 |
| Installation Type: | With Concrete |
| Diameter Anchoring hole: | 20 mm |
| Handling Key: | Hook Handle / 517082 |
| Locking Key: | CLE OTC N / 515485 |
Ductile iron manhole cover specifications and parameters
| Parameter | Specification/Value |
|---|---|
| Material | Ductile Cast Iron (Grade 500-7) |
| Standard Compliance | EN 124, BS 497, ASTM A536, ISO 1083 |
| Shape | Round, Square, Oval |
| Load Rating | A15, B125, C250, D400, E600, F900 (EN 124 load classes) |
| Load Bearing Capacity | 1.5 – 90 tons (depending on the rating) |
| Size (Diameter/Length) | 300mm – 1500mm (depending on type and design) |
| Thickness of Lid | 20mm – 60mm (depending on the load class) |
| Weight | 10 kg to 150 kg (depending on size and class) |
| Cover Surface | Smooth, Anti-slip, Textured for grip |
| Corrosion Resistance | Excellent, with epoxy coatings or bituminous treatment |
| Gasket Type | Rubber, Neoprene, EPDM |
| Sealing Mechanism | Bolt-down, Locking system, Hinged |
| Drainage Holes | Yes, optional (for water drainage) |
| Coating Type | Bitumen coated, Epoxy coating, Hot-dip galvanizing |
| Temperature Resistance | -30°C to +150°C (depending on coating type) |
| Fire Resistance | Flame-retardant (meets local standards for fire resistance) |
| Noise Level | Low noise design for urban areas |
| Ventilation | Optional vented covers for gas or sewage systems |
| Color | Black, Gray, Custom colors available |
| Manufacturing Process | Sand casting, Lost wax casting, Centrifugal casting |
| Edge Type | Flat, Raised, Beveled, or Reinforced edges |
| Bearing Surface | Cast iron, Epoxy, Stainless Steel (optional) |
| Longevity | 50+ years with proper maintenance |
| Environmental Compliance | RoHS, REACH, and other regional environmental standards |










