Frequently asked questions

Our ductile iron covers are cast to ASTM A536 Grade 65-45-12 (equivalent to QT500-7) and rated to AASHTO H-20 / HS-20 load classes with AASHTO M306 proof-load test reports. Composite covers carry CE conformity and EN 124 load-class testing (B125 through D400 depending on configuration). EN 124 ratings (A15 through F900) are also referenced for international equivalence. Material certs and load test records are prepared per project specification.

Yes. Our product range maps to the commonly referenced SPPWC plans — primarily the 630 series for manhole frame and cover sets. Additional configurations (302, 303, 304, 305, 312, 632, 633 series) are supplied to project drawings on request. Our Standards page lists the full crosswalk between SPPWC plan numbers and our product codes.

For configurations already on our standard tooling, plan on roughly 7–10 days of production per container, plus 25–30 days of ocean transit to U.S. West Coast ports (Los Angeles / Long Beach, Oakland) — about 5 weeks total. Larger orders running multiple containers scale production time proportionally. Custom configurations that require new tooling add 15–20 days up front for tooling fabrication and trial casting. Air freight is available for small or urgent shipments.

Our typical commercial MOQ is one 20- or 40-foot container per SKU — roughly 100–250 ductile iron manhole sets or 200–500 composite covers depending on size and weight. We can mix multiple SKUs within a single container to meet smaller per-SKU needs.

Yes. We routinely customize markings — SEWER, STORM, RECLAIMED WATER, ELECTRIC, city name, utility logo, ID number, and dated batch identifiers. Custom marking is part of the standard production workflow; we confirm artwork and rendering in writing before tooling release.

Ductile iron is the U.S. industry standard for traffic-rated applications — strong, heavy, recyclable, and certified to ASTM A536. Composite (BMC/SMC) is corrosion-immune, roughly 60% lighter to handle (a 24-inch composite assembly runs 99–132 lb vs 265–330 lb in ductile iron), has near-zero scrap value (a strong theft deterrent), and currently lands at a lower U.S. Section 301 tariff schedule (~7.5%) than ductile iron (~25%). Many utilities specify composite for theft-prone or coastal areas and ductile iron for heavy-traffic right-of-way.

Yes. Every order includes material chemistry analysis (spectroscopy), mechanical property test records (tensile, yield, elongation), and AASHTO M306 proof-load test reports for traffic-rated castings. Documentation format is matched to the project specification, and full-resolution copies of ISO / CE / EN 124 certificates are issued directly for procurement and submittal review.

Yes. Sample castings are available on a freight-charge basis, with the cost typically credited against the first production order. We confirm sample configuration, marking, and finish in writing before shipping.

All production is at our parent foundry — Hubei LZB Metal Products — in Wuhan, China. Ocean shipment is from Shanghai or Ningbo to your destination U.S. port. Our Irvine, California office handles U.S.-side documentation, drawing reviews, submittals, and clarifications.

Yes. ISO 9001 (quality), ISO 14001 (environmental), ISO 45001 (occupational health & safety), CE for both ductile iron and composite products, EN 124 load-class tested, IP-management certification, and SGS QIP-audited. Our Certifications page shows watermarked specimens; verified, full-resolution copies are issued directly for submittal packages.