What are the differences between Q235 steel and No. 45 steel plate?

The Q in Q235 steel means yield strength, 235 is yield strength, and the unit is kilogram force per square meter. Q235 steel is a kind of steel that is widely used. Some people usually call it rotten steel. For example, ordinary steel pipe materials are basically Q235 steel, which is generally used for profiles and bars. It was formerly called QA3 steel.

45# steel is a medium carbon steel with poor quenching performance. 45# steel can be hardened to HR2-46. 45# steel is widely used in machinery. This steel has good mechanical properties and its hardness is suitable for shaft parts and bolts.

Couplings and other parts. However, many bolts are low-carbon alloy steel, and the material should be selected according to the project details. If the surface hardness of 45# steel is required and the superior mechanical properties of 45# steel are desired, the surface of 45# steel is often carburized and quenched to obtain the required surface hardness.