H‑beam gantry welding machines are mainly categorized by welding mode, gantry structure and automation level. According to welding process, they are split into submerged‑arc welding type and gas‑shielded welding type. The submerged‑arc model delivers high welding quality for heavy‑duty H‑beams, while the gas‑shielded one fits light‑duty and thin‑wall workpieces.