MB40 Air-Cooled MIG Welding Torch

The MB40 (also known as BZ40) is Amalgum Welding Shop's air-cooled MIG welding torch for medium to heavy-duty work. Choose a 4m or 5m cable. It uses the M8 consumable range — the same thread as the water-cooled MB501.

What does "MB40" mean, and how heavy-duty is it?

MB40 is a torch style, not a brand name — it's a common connector and consumable standard used across several manufacturers. South African suppliers typically rate MB40-style air-cooled torches around 400A on CO2 shielding gas and 350A on mixed gas at a 60% duty cycle. Always check your specific welding machine and application against the torch and consumable ratings before ordering, since exact figures vary by manufacturer.

Should I choose air-cooled or water-cooled?

Air-cooled torches like the MB40 suit duty cycles up to around 50%. Water-cooled torches, like our MB501, are built for continuous production work at 60% duty cycle or higher — the water cooler pulls heat away faster than an air-cooled torch can. For most workshop and repair jobs, air-cooled is simpler to run and maintain.

What's included

The torch ships ready to connect to a compatible MIG welder. It doesn't include contact tips, gas nozzles or a liner beyond what's fitted — stock up separately using our MIG contact tips (M8 thread for this torch), gas nozzles and gas diffusers.

MB40 MIG welding torch FAQ

Is the MB40 the same as the MB501?

No. Both use M8 consumables, so contact tips and nozzles are shared. But the MB40 is air-cooled and the MB501 is water-cooled, needing a separate water cooler. Pick based on your duty cycle, not just amperage.

Will MB15 or MB25 contact tips fit the MB40?

No. MB15 and MB25-style torches take M6 thread. The MB40 takes M8. Check our MIG contact tips listing for both threads before ordering.

How do I know which cable length to choose?

4m suits a welder positioned close to the work. 5m gives more reach around larger fabrications or a machine set further back. Longer cables add a small amount of drag but don't change the torch's amperage rating.

Why does my MIG torch overheat during long welds?

Air-cooled torches rely on the cable and handle radiating heat into the air, which takes time. If you're running long, high-amperage welds back-to-back and the torch is overheating, you've likely exceeded its duty cycle — either work in shorter bursts, or move up to a water-cooled torch like the MB501.