WIX Archives
Re: On Americanizing...
Posted by Peter A on Fri Feb 20, 2004 07:30:09 PM
In reply top On Americanizing... posted by Joe Scheil on Fri Feb 20, 2004 06:21:59 PM
Joe
What are the normal characteristics of Americanizing?
To be Frank it has often been to run a 'US tap' through the British fitting!!!
Spitfires were built with BA ( British Association) thread size and standards up from 6BA, 4BA 2BA. 2BA is nominally 3/16 inch. Then they move on to Whitworth thread sizes and form at 1/4, 5/16, 3/8, 7/16 and 1/2. These are BSF British Standard Fine. There is a coarser thread BSW at each of these size but not seen on the Spitfire. Plumbing fittings are BSP British Standard Pipe size. All have their own spanner (wrench) and socket size different from all others. These threads went out of common usage in the 1950's to be replaced by the Unified range of threads UNF and UNC broadly in line I think with the US standard ANF and ANC but I suspect there are slight thread form variations.
Then it went to metric.
It is possible to get this early fasteners and fitting but when you consider the range required for a Spitfire it is horrendously expensive and time consuming to locate, paticularly if you are working long distance from the US.
PeterA