China Steel Manufacturing Guide
How steel is produced, how grades are specified across standards, and what the documents should tell you before material is shipped.
Two production routes
Most steel is made by one of two routes. The integrated route starts with iron ore and coke in a blast furnace, then refines the iron into steel in a basic oxygen furnace. The electric route melts scrap in an electric arc furnace. Both routes can produce the same grade; what differs is the raw material base and the typical residual element profile.
For a buyer, the practical consequence is that chemistry — not just the grade name — determines whether material behaves the way your application expects. That is why the heat analysis on a mill certificate matters more than the headline grade.
Grades mean different things in different standards
Grade designations come from national and international standards. Chinese material is commonly designated under GB, while buyers frequently specify ASTM, EN or JIS equivalents. These systems overlap but are not interchangeable: yield strength, chemistry tolerances and test requirements are defined separately in each.
When a specification is written, it is worth stating both the standard and the grade — for example a specific GB grade alongside the ASTM equivalent you are used to. That removes the most common source of disagreement between what was ordered and what arrives.
What processing changes
Hot rolling, cold rolling, annealing, galvanizing and organic coating each alter the surface, the tolerance, or the mechanical properties of the same base steel. Two products that share a grade can therefore behave very differently in service.
This is the reason a specification should describe the finished condition — form, surface, coating, tolerance — rather than only the base grade.
Documents to expect
A mill test certificate reports the heat analysis and mechanical results for the material supplied. For coated or processed material, additional information on coating mass or surface treatment is normally provided separately.
It is reasonable to ask, before ordering, which documents will accompany the shipment and who issues each one. If a document cannot be provided for a particular product, that is better established in advance than at the port.