PURPOSE: To make it possible to manufacture gratings by a small scale equipment by bending and machining straight line sections having a specific width and diagonal sections in a zig-zag shape in succession with strip steel plates, etc., and welding and fixing contacts of the straight line sections and diagonal section with short straight line sections.

CONSTITUTION: A grating body is constituted of straight line sections 1 having a specific width and bending line sections 3 formed of diagonal sections 5 formed by turning at turning sections 2 and 4 and short straight line sections 6. Contacts 7 bringing the diagonal sections 5 from the turning sections 2 and the short straight line sections 6 into contact with the straight line sections 1 are provided, they are welded and fixed with the contacts 7 from the front and rear sides, and side plates 8 and 9 are also fixed to both sides. According to the constitution, panel cutting, lug cutting, etc., are not required, and gratings can be manufactured by a small scale equipment.