Quality Control

Rigorous quality assurance from raw material to finished product. ISO 9001 certified, EN124 compliant.

Our Quality Philosophy

At Guanxing Casting, quality is not an afterthought — it's built into every step of the manufacturing process. Our ISO 9001:2015 certified quality management system ensures that every manhole cover leaving our factory meets or exceeds EN124:2015 requirements.

We don't just test finished products. We control quality at five critical stages: raw material, melting, casting, machining, and final inspection.

Five-Stage Quality Control Process

1

Raw Material Inspection

  • • Chemical composition analysis via spectrometer for every iron batch
  • • Verification of GGG50 grade (Carbon 3.5-3.9%, Silicon 2.0-2.8%, Magnesium 0.03-0.06%)
  • • Incoming inspection of all alloys, inoculants, and coating materials
  • • Supplier qualification and material traceability system
2

Melting & Treatment Control

  • • Temperature monitoring: Pouring temperature 1,350-1,420°C
  • • Magnesium treatment verification (nodularization process)
  • • Inoculation timing and quantity control
  • • Wedge test on every ladle to verify nodularity before pouring
3

Casting Process Control

  • • Mold inspection before every pour (pattern wear, alignment)
  • • Sand quality testing (moisture, permeability, compressive strength)
  • • Pouring rate and temperature monitoring
  • • Cooling rate control to ensure proper microstructure formation
4

Machining & Finishing

  • • CNC machining of seating surfaces to ±0.5mm tolerance
  • • Dimensional inspection of frame and cover (100% inspection)
  • • Coating application: thickness measurement and adhesion testing
  • • Assembly verification: cover fit, locking mechanism functionality
5

Final Inspection & Testing

  • • Load testing: Random sample from each batch tested at class load
  • • Visual inspection: 100% inspection for surface defects, coating quality
  • • Dimensional verification: Critical dimensions checked on every unit
  • • Functional testing: Lock operation, hinge movement, seating verification
  • • Weight verification: Every set weighed against specification

Testing Laboratory Equipment

Chemical Analysis

Optical emission spectrometer for rapid (30-second) chemical composition verification of every iron batch. Tests 18 elements including C, Si, Mn, P, S, Mg, Cu, Cr.

Mechanical Testing

Universal testing machine (600kN capacity) for tensile strength, yield strength, and elongation testing per ISO 6892-1. Brinell hardness tester per ISO 6506.

Metallographic Analysis

Inverted metallurgical microscope with image analysis software for graphite nodularity assessment (target ≥80%) and matrix structure verification.

Load Testing

Dedicated EN124 load test frame with hydraulic actuator and digital force measurement. Tests at class-defined forces with automated cycling capability.

Dimensional Measurement

Coordinate measuring machine (CMM) and digital calipers. Go/No-Go gauges for critical fits. Surface roughness tester per ISO 4287.

Coating Inspection

Digital coating thickness gauge (magnetic induction). Cross-cut adhesion tester per ISO 2409. Salt spray chamber for corrosion resistance testing.

Certifications

ISO 9001

Quality Management System — 2015 version

ISO 14001

Environmental Management System

EN124

Manhole Cover Product Standard — 2015

CE

European Conformity Marking

Third-Party Inspection

We welcome and encourage third-party inspection by recognized agencies:

  • • SGS — Société Générale de Surveillance
  • • Bureau Veritas — Global testing and inspection
  • • TÜV Rheinland / TÜV SÜD — German technical inspection
  • • Your nominated inspector — Any qualified third party

Inspection scope can include raw material verification, in-process audits, pre-shipment inspection, and witnessed load testing.

Documentation You Receive

Every export order includes a complete quality documentation package:

  • • Material Test Certificate (EN 10204 3.1) — Chemical composition + mechanical properties
  • • EN124 Load Test Report for the production batch
  • • Dimensional Inspection Report
  • • Coating Thickness and Adhesion Report
  • • Certificate of Conformity
  • • ISO 9001 Certificate (copy)

Quality You Can Verify

Request our quality documentation package or arrange a third-party inspection for your order.

Request Quality Documents