Bester Feed Rolls FAQs
Straight answers to the questions people ask most when choosing and looking after replacement feed rolls for a MIG wire feeder.
Which feed roll groove do I need for solid steel or stainless wire?
A V-groove roll is the usual choice for solid steel and stainless steel wire. The V shape grips the wire and feeds it without slipping or squashing it, so you get a steady wire speed at the tip.
The groove must also be the right size for the wire diameter, so check the diameter printed on the spool and the size marked on the roll before you order. Your welder's manual will say which roll types suit your feeder.
Do I need a knurled roll for cored wire?
Flux-cored and metal-cored wires usually need a V-groove roll with a knurled (toothed) surface. Cored wire is a thin tube filled with flux or metal powder, and a smooth roll needs a lot of pressure to grip it, which can crush the wire.
The knurling bites into the outer shell, so the wire feeds with less tension and keeps its shape. Do not use a knurled roll on solid wire as a general rule, because the teeth can mark it and shave fine metal into the liner.
How do I know which side of the roll to use?
Many rolls have two grooves, one on each face, for two neighbouring wire sizes. The size is normally marked on the roll. The side facing outward or inward depends on your feeder, so follow the manual.
Fitting the roll with the wrong size groove in the working position over-tightens or loosens the grip on the wire, which causes slipping, deformed wire and poor feeding. Always check the size marking against the wire diameter every time you change roll or wire.
How do I tell when feed rolls are worn out?
Signs include the wire slipping or feeding unevenly even though the tension seems right, a polished or flattened groove, or knurling that has worn smooth. Worn rolls make it hard to reach the right pressure, and wear tempts people to keep tightening the tension, which deforms the wire.
Inspect the rolls regularly, for example whenever you fit a new spool, and clean or replace any that are deformed. There is no fixed life, so replace them when feeding turns erratic with the right settings. Check the liner, guides and contact tip too, as they can cause the same symptoms.