1. **How to tell if rebar is galvanized?**
Visually inspect the surface for a characteristic bright, spangled (crystalline) pattern or a uniform dull grey finish. Galvanized rebar will not have red rust; instead, it may develop white, powdery zinc oxide/carbonate corrosion products. A definitive test is scraping the surface lightly with a wire brush or knife in an inconspicuous area – bright, silvery metal underneath a grey layer confirms galvanizing.
2. **What is S275 galvanized steel grade?**
S275 is a structural steel grade per the European standard EN 10025 (specifically EN 10025-2). "Galvanized" refers to a zinc coating applied *after* the steel is produced to the S275 grade specification. S275JR is the most common sub-grade, with a minimum yield strength of 275 MPa.
3. **What is the yield strength of S235 steel?**
The minimum yield strength (ReH) for S235 structural steel (specifically the common S235JR grade per EN 10025-2), for nominal thicknesses ≤ 16mm, is **235 MPa**.
4. **What are the two grades of galvanized pipe?**
Two common grades of steel pipe that are frequently galvanized are **ASTM A53 (Type E or F, Grade B)** and **ASTM A106 (Grade B)**. In China, commonly galvanized pipe grades include **GB/T 3091 (Q235B)**.
5. **What is S275 steel equivalent in China?**
The closest equivalent structural steel grade to European S275JR (EN 10025-2) in the Chinese standard GB/T 700 is **Q235B**. However, mechanical property requirements (especially impact toughness) differ slightly, so direct equivalence depends on the specific application requirements.
