During factory audit of crawler cranes, which structural weld and NDT reports must be verified?

• Verify UT/MT reports for main boom, mast, and turntable welds with 100% coverage.
• Require welder qualification certificates per ISO 9606 or AWS D1.1.
• Check structural steel certificates; Q690 high-strength steel needs third-party re-test.
• Confirm WPQR covers all joint types used in fabrication.
• Spot-check critical welds on site, record defect grades and repair logs.