Morris Minor Owners Club

7/16 AF , 5/8 AF ,3/8 w- what is this AF / w ? Can you give me its from mm or inch ?

A/F = Across the Flats, the width of the spanner jaws in inches. Fits unified fine and unified course (unf and unc) threads.
Whitworth = the bolt thread diameter in inches. Fits British Standard Fine and British Standard Course (BSF and BSW) threads, mostly found on the bodywork of a Minor.
The spanner sizes are very close, 1/4 W is slightly bigger than 1/2 A/F. Do not mix the spanners or you will round the hex.
Forget about metric mm on a Minor

You'll find many articles on this subject:

http://en.wikipedia.org/wiki/British_Standard_Whitworth explains the basics of Whitworth, BSW, and BSF threads.

http://www.sat.dundee.ac.uk/~psc/spanner_jaw.html contains excellent explanations and a very useful chart, a copy of which I have on my garage wall.

Kevin

The only useful metric socket is an 18mm - which is a good fit for the wheel nuts!

bmcecosse wrote:The only useful metric socket is an 18mm - which is a good fit for the wheel nuts!

11mm spanners are also useful which is a VERY close fit for 7/16 AF, as in brake nipples and unions etc.

Other than that, you need a set of A/F spanners and sockets for the engine/some suspension and a set of Whitworth spanners and sockets for the body/ suspension etc.

If 11mm is a very close fit for a 7/16 a/f then use a 7/16 a/f

mike.perry wrote:If 11mm is a very close fit for a 7/16 a/f then use a 7/16 a/f

Exactly! As indeed I do. 11mm and 18mm are the only metric sizes that are close enough to work well. All other attempts to use metric tools to undo A/F or Whitworth fixings is bodgery!

But in this particular case I also have an 11mm Sykes Pickavant brake spanner and it works brilliantly on 7/16 AF brake bleed nipples and brake unions.

The only reason I have an 18mm socket is because I was struggling to find the correct wheelnut socket for a spare to carry under the seat in the car - and the 18mm was £1 at an autojumble.....