What is the negative deviation allowed by the national standard for galvanized flat steel of 40*4?
40 is the width of the section steel, 4 is the thickness of the steel, and the unit is mm.Flat, refers to the width 12-300mm, thickness 4-60mm, cross section is rectangular in shape and with a blunt edge of steel. Flat steel can be finished steel, or can be used as the blank of welded pipe and thin slab for laminated sheet rolling.
40*4 galvanized flat steel GB permitted negative deviation value is the thickness deviation value is 0.2mm, the deviation 0.4mm, the width deviation value is the upper deviation 0.5mm, lower deviation 1.0mm
