Japanese standard steel profiles, mainly governed by JIS G3192 and JIS G3193, have precise dimensional specifications. For angle steel (L - shaped), leg lengths typically range from 20 mm × 20 mm to 200 mm × 200 mm, with thicknesses from 3 mm to 25 mm. Channel steel (C - shaped) has heights varying from 50 mm to 400 mm, flange widths from 37 mm to 102 mm, and web thicknesses from 4.5 mm to 14.5 mm. I - beams (H - shaped) can have heights up to 1000 mm, flange widths up to 300 mm, and thicknesses adjusted according to load - bearing requirements.
Compared with other standards, Japanese profiles often feature more refined tolerances. For example, the allowable deviation in leg length for JIS angle steel is stricter, ensuring better fit - up in assembly. JIS also has unique profile shapes in some special - purpose steels, which are tailored to meet the specific needs of Japanese industries, such as the high - precision requirements in the electronics manufacturing - related construction.