1, workshop crane lifting weight: greater than or equal to 25T, can be considered as the heavy steel structure.

2, the amount of steel: greater than or equal to 50KG/㎡, can be considered as heavy steel structure.

3, the thickness of the steel plate of the main member: greater than or equal to 10MM, less light steel structure.

In addition, there are some reference values: such as each ** cost, ** component weight, ** span, structural form, eaves high, these can provide empirical data in judging whether the plant is heavy steel or light steel, of course, many buildings are light and heavy steel have. But there are some we can say with more certainty is heavy steel: such as: petrochemical plant facilities, power plant, large-span stadiums, exhibitions, high-rise or ** layer steel structure.

In fact, national norms and technical documents are not said chonggang, in order to distinguish light housing steel structure, perhaps called general steel structure 'Pugang' more appropriate. Because the scope of ordinary steel structure is very wide, can contain all kinds of steel structure, no matter the load size, even including many content of light steel structure, light housing steel structure technical specification only for its' light 'characteristics and provide some more specific content, and the scope is only limited to the single-layer portal frame.

Light steel is also a more ambiguous term, generally can have two kinds of understanding. One is the current "Code for Design of Steel Structures" (GBJ 17-88) in chapter 11 'light steel structure of round steel and small Angle steel', refers to the light steel structure made of round steel and Angle steel less than L45*4 and L56*36*4

This shows, light steel and heavy steel of the cent is not in the weight of the structure itself, and in the weight of the envelope material that bear, and on structural design concept or consistent.