Aluminum welding wire ER4043 is a general-purpose type aluminum welding wire. It contains silicon additives, which result in improved fluidity (wetting action) of the weld pool and also produces a weld less sensitive to cracking. Its bright weld finish makes it a popular choice of welders. It can be used to weld various grades of aluminum. 0.030-Inch wire diameter ER4043 1-Pound spool