The 'e' in E6013 or E7018

[slim_boy_fat]

2,3,4&5 are also the categories of undesirable women to avoid when your drunk

fftopic: But they all look like 8 - 10s when the beer goggles are being worn.

 

[KrisG91]

Found this in BS EN ISO 18275:2018

5 Symbols and requirements
5.1 Symbol for the product/process

The symbol for the covered electrode used in the manual metal arc process shall be the letter E.

 

[Agroshield]

...Consulting The Science and Practice of Welding by A. C. Davies, fifth edition, it could be strongly argued that the E is for 'extruded'; in comparison to 'dipped' for example. Hence, the 'E' is in reference to the manufacturing process of the electrode.View attachment 228999

The E, R or D in your book refers simply to the method by which the flux is applied to the metal electrode. It is likely that since the book was written, the D method of manufacture has fallen out of use (possibly too slow, too expensive, not consistent enough, etc.). So if every electrode made today has the flux applied by extrusion, the designation actually becomes redundant as you have no other choice. It has therefore morphed into an identifier for a MMA consumable to distinguish it from other-process-consumables.

If you look on YT at electrode manufacturing videos, the bare wire goes in one end of the machine (the sausage) and a long, coated electrode (the sausage roll) comes out of the other. It is then chopped to length, the uncured flux removed from the stinger end and then baked to cure the flux.

Thus is wild speculation but the R designation sounds like it might be used for specialised electrodes with a particularly thick flux on them (someone posted pictures of a 3/4" dia. one) where the flux might be too fragile if unreinforced.

 

[marky123]

When I worked at an electrode manufacturers,the filler wire was precut.