1957 1/4 flat washers

[Dan P.]

T

he AM shows 2 different part numbers for the flat washers for 1/4 bolts .120392 and 120385 I believe one is USS and the other is SAE. I had all my hardware plated and there are 2 different size washers .So could someone measure the OD of the 1/4" flat washers that mount the inner fenders to the cowl 120392 on a unrestored car .Thanks in advance

[David B.]

Re: 1957 1/4 flat washers

120392 SAE 1/4 zinc .281 inside X .625 OD X .065 thick
120385 3/16 zinc .250 inside X .562 OD X .049 thick

[Dan P.]

Re: 1957 1/4 flat washers

What makes this so confusing is in the AM

120385 is shown as the flat washer for 3/16 recessed head bolts for the lower filler panel and also shown for the 1/4 bolts that hold the hood strikers on .
120393 is shown convertible top cover bolts while 120380 is shown for the decklid bolts . They are the same washer. 120393 is shown for the horn bolts which are 5/16??