||"The paper includes summaries of three national development projects, which all deal with product modelling and data exchange of structural steelwork. Two of the projects belong to Finnsteel technology program, one belongs to Vera technology program and both these programs are organized by TEKES of Finland.In all the three projects product data models applying ISO 10303-11 (EXPRESS) and product data exchange based on ISO 10303-21 have been used to define the models and to carry out the data exchange between organizations and between disciplines. The views to structural steelwork have been different in all the projects. The first project is called SteelBase, the second FST-EXPERT and the third FinnST-1.The largest project, SteelBase (three years, 28 companies) was focused to the data exchange between the steel designer and the steel product fabricator and to the education of the creator and the end user of the product data. The second project, FST-EXPERT was mainly focused to the product modelling and to the data exchange between geometrical modelling, structural analysis and cost estimation i.e data exchange within the organization but between disciplines. The third project, FinnST-1 is scoped to the structural steelwork data exchange between organizations generally. FinnST-1 project includes mapping between the CIMsteel Integration Standards from the CIMsteel Eureka project and the Industry Foundation Classes from the International Alliance for Interoperability.All the projects include much basic studies within the field of product modelling, some new findings and a lot of experience for the people involved with the projects. It is believed, that this experience is a good starting point to the new century with its challenges. The most essential results of the three projects are presented and summarized in the paper.Some results are e.g. (SteelBase) evaluation of possible STEP based product models for steel structures, basic data definitions needed for the data exchange between the designer and the fabricator, and the effect of that definition to the CIMsteel standard (from R1.1 to R2.0), mapping of product data following the needs of different organizations, and the importance of the education for these new things. In FST-EXPERT project it is shown, that the mapping with some ""intelligence"" between the geometrical model and the structural analysis (FEM) model can be a powerful tool if neutral data files are used for the data exchange. The power means here total independency of the CAD-program and the FEM-program and moreover in this case the cost estimation and strength check can be integrated to the design process applying neutral STEP-files. Finally, FinnST-1 project brings all the work done in the other projects to the use of all the organizations involved into the building project. Also, the possibilities to perform the mapping between STEP-models are new information."