Fe35 FAQs
Straight answers to the questions people ask when choosing and replacing consumable parts for this class of MIG torch.
How do I know when to change a MIG contact tip?
Look at the hole in the tip. A new one is round; as it wears it becomes oval or enlarged, and the arc starts to wander, the wire feeds unevenly or it keeps burning back into the tip. A tip clogged with spatter at the entrance also makes feeding harder.
Inspecting the tip before each welding session is a good habit, and heavy use wears tips faster. Change it as soon as the bore is no longer round rather than waiting for it to fail.
Why is there a separate contact tip for aluminium?
Aluminium wire is soft and expands more than steel as it heats, so aluminium tips are made with a slightly larger bore to stop the wire jamming and tangling in the feed system. Using a tip made for steel with aluminium wire can give poor contact and feeding trouble.
Buy tips marked for aluminium, and keep them separate from the tips you use for steel so they do not get mixed up. Check the torch maker's recommendation for the wire size you are using.
When is a heavy-duty or chrome zirconium contact tip worth choosing?
These tips are made from a harder copper alloy that resists softening at high temperature. That helps the bore stay round for longer, so they are often chosen for high currents, long arc-on times and demanding work, including stainless steel.
Standard copper tips conduct well and suit lighter or occasional work. The right choice depends on the current, the duty cycle and the wire, so follow the torch maker's guidance. Whatever you pick, it must fit your torch's thread and your wire size.
What types of gas nozzle are there and which should I choose?
Cylindrical nozzles give the widest gas coverage and suit higher currents and larger contact tips. Conical and tapered nozzles narrow towards the end, which gives better access in tight corners and T-joints but may collect spatter more quickly.
A sensible rule is to choose the largest nozzle that still lets you see and reach the joint. Make sure the nozzle is the type designed for your torch, because threads and fittings differ between torch families.