Fe35 FAQs
Straight answers to the questions people ask when choosing and replacing consumable parts for this class of MIG torch.
How do I choose the right size of contact tip?
The bore should match the wire diameter, with just enough clearance for the wire to feed smoothly. A tip that is too large loses steady electrical contact and tends to cause burn-back; one that is too tight can jam the wire.
Tips are sold for each wire size, and also for each thread and torch type, so check both the wire diameter you use and the thread on your torch before choosing. Your torch manual will list the correct tip.
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.