I think I understand what stand is asking for. He wants to know the formula to calculate the weight of welded metal deposited into a joint, how many electrodes were necessary to make that joint, how to measure (weight) the welded metal after the weld is ready, and how to convert unit of thickness gage to millimeters.
And here goes my answer, taking covered (stick) eletrodes as an example.
1. There are many tables that show the weight of welded metal within a joint, depending on the joint thickness and shape. Companies like Lincoln, ESAB, Hobart and others have published such tables in their books and catalogs. Most of them are supplied free if you ask them. Visit Lincoln, ESAB and Hobart sites, which you'll find as a link in this same AWS site.
2. Once you know the weight of the welded metal, divide it by 0.6 and you'll have, roughly, the weight of covered electrodes that were necessary. Where does that figure come from? It's a "rule of thumb" figure which has demonstrated to be reliable.
3. The only way to measure the weight of the welded metal would be to weight it on a scale. In the majority of cases, of course, this is unfeasible. So, you'll have to rely on the first two steps I've described.
4. There are several Gages to measure thickness. The most popular in the U.S.A. is the MSG (Manufacturers Standard Gage). In Great Britain and some Latin American countries like mine is the BWG (Birmingham Wire Gage). In France is the JP (Jauge de Paris). Any engineering handbook has a table showing the conversion of any of them to millimeters.
Satisfied with the answer?
Giovanni S. Crisi
Sao Paulo - Brazil