Metal Cored Wire
Metal-cored MIG welding wire - 70C-6M, a composite electrode for high deposition rates on production fabrication.
Metal-cored is not flux-cored
The name invites the confusion, so be clear: a metal-cored wire has a metal powder core, not a flux core. It produces almost no slag - a few silicon islands you brush off, rather than a crust you chip. Functionally it behaves like a solid wire with a much higher deposition rate, not like a flux-cored wire.
It needs shielding gas, and it does not tolerate wind any better than solid MIG does.
Where it earns its price premium
Metal-cored wire costs more per pound than solid wire and it is bought for throughput, not for cost per pound.
- Higher deposition rate at the same amperage - more metal in the joint per minute, which on long production seams is the whole argument.
- A broader, more forgiving arc cone that tolerates mill scale and marginal fit-up better than solid wire.
- Wider penetration profile, which reduces the risk of the narrow finger-shaped penetration that causes lack of fusion at the toes.
- Less spatter and virtually no slag, which cuts post-weld cleanup - often the real saving.
On short welds, repair work and low duty cycles, solid wire is the better economics and there is no shame in saying so.
It wants spray transfer and mixed gas
Metal-cored wire is at its best in spray transfer, which needs an argon-rich mix and enough voltage to get there - typically 75/25 or richer in argon, not straight CO2. Run it in short-circuit mode at low parameters and you lose the deposition advantage you paid for.
Check that the machine has the output to hold spray transfer at the wire diameter and duty cycle you intend. This is a production wire and it expects a production machine.
The 6M classification
70C-6M denotes a 70,000 psi tensile composite electrode for mild and low-alloy steel, mixed-gas rated. It is the general-purpose metal-cored wire and it covers the majority of structural and fabrication work in that strength class.
Free shipping over $175 across Canada. Counter pickup in North York - and if you are weighing metal-cored against solid wire for a specific job, call us with the joint and the volume and we will give you a straight answer.
