when rod goes to be cut by rod cutting machine, the result is a production called length. usually lengths have different strength and springy properties from their initial rod. machine for producing length is a device which rod set in without any bending and cut to ordered sizes by clients. cutting rod to length, increases bending strength and springy properties. length has more stiffness than rod, because of this it is used as chassis and main structure of different instrument including main body of travel tent and spring mattress. for travel tent, depending on its size, different diameters of length used. for car sun shade, usually 1.8 diameter length is used. while, length in spring mattress is 4 mm in diameter.
