It involves using low-strength Q235 steel to impersonate high-strength, high-value Q355 steel.

The core properties differ: Q235 is carbon structural steel with a yield strength of approximately 235 MPa; while Q355 is low-alloy high-strength steel with a yield strength of at least 355 MPa and significantly higher tensile strength. Q355 has superior overall performance due to the addition of more alloying elements (such as manganese).

Because of its superior performance, Q355 is more expensive. Unscrupulous merchants use Q235 to impersonate Q355 for illegal profit.

Using Q235 instead of Q355 would significantly reduce the load-bearing capacity of the building's main structure, seriously jeopardizing the inherent safety of the project.

Because they look almost identical, and are even more difficult to distinguish after painting, professional methods are needed to prevent counterfeiting.
First, check the material certificate, verifying each item's grade, performance indicators, official seal, and batch number, and checking for any alterations.
Seek third-party testing. Testing personnel will use a handheld spectrometer to test the content of key elements such as carbon and manganese on-site to ensure they meet standards.
Entrust a qualified institution to conduct comprehensive testing on the steel's chemical composition and mechanical properties (yield strength, tensile strength), etc.

Time：06/07/2026 17:29:48

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