Product Overview Manufactured by Dongguang Hengfu Roll Forming Machine Co., Ltd. The YX21-164-820 roll forming production line is a popular high-speed automatic trapezoidal roof panel machine well received by metal-sheet processors worldwide. It realizes full-process automatic production — from coil decoiling, material guiding, roll forming and fixed-length shearing through to finished panel discharging — turning raw color-coated steel coils into standard YX21-164-820 roof