I may of misunderstood your question but above the table on the link I posted it gives the differences of the forms A,B,C,D in terms of outside diameter and thickness etc
“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein
I'd assume BS 3410 and BS 4320 are a couple of the codes being referenced - just guessing based on Forms and Tables being referenced. DesertFox linked a BS4320 Form chart.
Firstly I said :- "I might havr misunderstood your post" I never said you misunderstood mine.
Your question was what was the diference between form A.B.C. D washers, where in your question does it mention any washer specifications BS3410 BS4310?
Had you mentioned them in your original post I might have answered differently, quoting a TABLE 3,4,7,8 doesnt tell me the specifications.
“Do not worry about your problems with mathematics, I assure you mine are far greater.” Albert Einstein
OKAY, THANKS SORRY FOR THE MISUNDERSTANDING. i THUGHT i HAD MENTIONED THE FORM SPEC AND TABLE SPEC, BUT OBBIOSLY IT WASNT CLEAR, I.E SOMETIMES A TABLE IS SPECIFIED WHILE SOMETIMES A FORM IS SPECIFIED, ALL VERY CONFUSING