Millimeters Matter: Anchor Bolt Accuracy Is Erection's First Test

Perfect fabrication is useless if anchor bolts are misplaced. Field-tested ways to hold ±2mm.

Export members are fabricated in the factory to ±2mm — but anchor bolts are set by the owner's civil crew, and if they drift, the first shipment simply won't fit.

Practical field experience: verify the control grid with the civil contractor before setting, and use positioning fixtures instead of tying bolts directly to rebar; re-survey after pouring and before members arrive so deviations can be corrected with shim plates; and mark bolt projection length and thread protection clearly on the erection drawings.

Xionglan ships a bolt-position acceptance checklist with the drawings, so most local crews can self-check successfully. Finding a deviation two days early is a very different experience from finding it when the steel arrives.