24" Round Ductile Iron Manhole Cover & Frame
AASHTO H-20 traffic rated, anti-settlement design
Workhorse 24" round sanitary sewer / storm cover and frame set. Cast to ASTM A536 Grade 65-45-12 (QT500-7), AASHTO H-20 / D400 proof-load rated, with anti-settlement wide rim and U.S. precast-compatible dimensions.
| Product Code | LZB-DI-R24-D400 |
|---|---|
| Clear Opening | 24" (610 mm) |
| Overall Size | ~40" OD frame (1000 mm) |
| Cover Thickness | ~1.5" (38 mm) |
| Frame Height | ~7.5" (190 mm) |
| Material | Ductile Iron QT500-7 |
| U.S. Material Equivalent | ASTM A536 Grade 65-45-12 |
| Load Rating | AASHTO H-20 / D400 (40,000 lb proof load) |
| Assembly Weight | 265–330 lb (120–150 kg) assembly |
| Surface Finish | Black bituminous coating |
| Marking | Customizable — SEWER, STORM, city name, utility logo |
| Locking | Elastic locking device standard; bolt-down optional |
- · ASTM A536 Grade 65-45-12 (material)
- · AASHTO H-20 / HS-20 (load)
- · AASHTO M306 (proof load test)
Meets the SPPWC 630-5 configuration referenced by the City of Los Angeles, Irvine, Anaheim, Fullerton, Caltrans, LACDPW, and 30+ Southern California agencies.
Why specify this
- ✓ Non-rocking integrated casting — no shift or rattle under traffic
- ✓ Anti-settlement wide rim distributes load to prevent road surface settling
- ✓ 180° hinge with stainless steel pins for safe maintenance access
- ✓ Custom markings — SEWER / STORM / city or utility ID
- ✓ Precast compatible — drops into standard U.S. concrete manhole cones
The 24” round cover is the most-specified configuration for sanitary sewer and storm-drainage manholes across U.S. municipalities. This set is engineered for direct drop-in on standard precast concrete cones — frame OD and rim profile match the eccentric/concentric cone industry standard, so no field grinding or shim work is required.
The anti-settlement wide rim transfers vehicle load to the surrounding asphalt or concrete pavement rather than concentrating it at the rim of the casting, which is the failure mode that causes the common “rim crater” around aging covers. The cover itself is a single integrated casting (no welded inserts) for non-rocking seating and a long service life under cyclic traffic.
ASTM A536 65-45-12 material documentation, AASHTO M306 proof-load test records, and project-specific marking confirmations are prepared per RFQ.
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