VR400THF Professional MMA Welding Machines

OTC DAIHEN VR400THF IGBT Inverter DC TIG/Stick Welder

The VR400THF is a DC TIG/stick welder from OTC DAIHEN, featuring advanced IGBT inverter technology. With a minimum TIG output of only 4A, it excels in thin‑plate and precision welding. An optional remote control with auto‑detection eliminates panel switching, making parameter setting more convenient. Safety features include an automatic gas shut‑off after 2 minutes of no welding, plus comprehensive protection circuits. Advanced IGBT design and a newly developed high‑frequency circuit ensure easy arc starting and instantaneous arc ignition. The stackable design (upper unit’s feet fit into lower unit’s handle) saves valuable workspace. Widely used in oil & gas pipelines, pressure vessels, construction, and repair applications.

✨ Key Technology Advantages

• 4A minimum TIG current — Ideal for thin‑plate and precision work.

• Remote control auto‑detect — No panel switching, easy setup.

• 2‑min gas shutoff safety — Saves gas, enhances safety.

• IGBT + HF start — Easy arc starting, stable instantaneous ignition.

• Stackable design — Space‑saving, convenient for multi‑unit use.

• Wide application — Pipelines, pressure vessels, construction, repair.

• Multiple protections — Overcurrent, overheat, etc., for safe operation.

🔧 Primary Applications

Oil & gas pipeline welding, pressure vessel fabrication, construction steel installation, on‑site repairs – especially where thin‑plate capability and portability are required.

📊 OTC DAIHEN VR400THF Technical Specifications