Bulgarian (BDS) Standards for Steel Materials
                                            
                                            This comprehensive collection of Bulgarian (BDS) standards encompasses carbon, alloy, and structural steels, including free-cutting steels, pressure vessel plates, hot-rolled materials, high-temperature steel castings, welding filler rods, tool steels, and electrical quality steels. The BDS standards review comprises four volumes containing formally approved classifications, guides, practices, specifications, test methods, and terminology. The documentation covers four primary steel categories.