Electrode consumption calculator
How many kilograms of electrodes a job needs — and therefore how many packets to order. The calculation goes through the deposited metal, which is the only honest way to do it.
How it is worked out
First the cross-sectional area of the weld: for a fillet it is
z² / 2 plus about 10 % for convexity; for a V butt it comes
from the included angle, the thickness, the root gap and the root face.
Multiplying by the length and by the density of steel, 7.85 g/cm³, gives the
mass of deposited metal.
The mass of electrodes is larger than that, because the stub, the coating and the spatter never reach the joint. The loss factor covers this: 1.5 for careful shop work, 1.6 typically, 1.7 on site and overhead, 1.8 where conditions are bad enough that you would rather not know.
Ordering by the result
Round up to whole packets and add one. Electrodes that stay dry keep; a job stopped at four in the afternoon because a packet ran out costs more than the packet. If the material is a basic type, remember that an opened packet needs re-baking after a shift in humid air — see electrode coating types.
Updated: