EN 1090 is the EU gateway for structural steel. This guide explains EN 1090-1/-2, execution classes EXC1 to EXC4, CE marking, the Declaration of Performance, and what to specify when buying structural steel for the European market.
P = 2St/D explained with yield, code-allowable and mill-test worked examples, thin-wall limits, and how to reverse it for ordering wall thickness.
What random, single-random, double-random and exact lengths mean in practice, why they price differently, and how to write length into a PO.
Verified wall and OD tolerance tables across the four standard families, nominal-wall vs minimum-wall logic, and how to write tolerances into a PO.
Container and break-bulk packing practice for carbon steel pipe: end protection, VCI and rust control, strapping, coated pipe handling and claim-proof photos.
Why idler tube is not ordinary pipe — end-zone OD and ovality, straightness, wall uniformity, manufacturing routes and what OEMs actually specify.
Augers, drilling buckets and core barrels explained — body materials, tooth systems, kelly box interfaces and what separates a good fabrication.
Frame members and typical sizes, pre-galv vs hot-dip vs ZAM economics, relevant standards, and arrival checks for greenhouse tube orders.
What heat and product analysis each represent, how product analysis tolerances work under ASTM A751 and GB/T 222, and the right escalation path in disputes.
How mill hydro test pressures are calculated (P = 2St/D), what API 5L, ASTM and GB/T require, and what to watch when witnessing the test.