F-Number and A-Number

[AWeld1]

If "P" stands for pressure in P-No. then "S" for structural in S-No., I would like to know what what does F and A means?
As per QW-442 A.No is for the Classification of Ferrous Weld Metal Analysis for Procedure Qualification and QW-432 F-Number is for Grouping of Electrodes and welding rods for Qualification.

Why is "F" and "A" were used for F-Number and A-Number respectively?
Does "F" means filler and "A" means analysis?

Thank you very much.

 

[weldstan]

P does not stand for pressure. It's just a designator for grouping of materials from a weldability standpoint.
F designates welding filler metal with the number after further defining characteristics
A number defines chemical analysis limits for specific alloy steels.

 

[Inspectoriam]

ASME is no longer using the S symbol for API materials.