Correctly measuring imperial socket size

[markbg]

Hi,

 

I have a FOX CVRW and I need to get a socket that fits a bolt on the FOX - this bolt is the same size on the hubs the drain plugs and gearbox plug. The bolt is made of brass but Ive tried a 30mm socket (slightly too big) and 27mm which is too small. What I need to know is how I measure the bolt head to order the correct imperial socket?

 

Do I measure the diameter in imperial units?

 

Any advice appreciated!

 

thanks

 

Mark

[antarmike]

It could be 1 1/8" which is 28.575mm

 

1 1/16" is smaller than the 27mm you have tried (26.9875mm)

 

the only other inch size near this size is 1 3/16" which is bigger than the 30mm you have already tried (30.163mm)

 

so unless it is a BSF/ or BSW bolt it has to be 1 1/8" A/F.

 

If it is BSF/ BSW the only contender is 5/8"W, 11/16" BSF which is 27.94mm.

 

9/16"W, 5/8"BSF is too small at 25.76mm and 11/16"W, 3/4"BSF is too big at 30.48mm

 

It has to be either an 1 1/8" A/F or an 5/8"W, 11/16" BSF Socket you need.

 

If it is a drain pug it could be a BSP thread, so it is likely to be a BSW, BSF size but the Fox experts will tell you.

 

or you could measure with a rule or a caliper....Best to do it in metric, and cross reference to the metric size equivilents I have quoted, unless you have an "aircraft" rule (also sold as Aircraft Quick Reading or AQR) graduated in tenths and hundredths (1/10, 1/100) rather than an engineers rule graduated in 1/64", 1/32" 1/16"etc

 

The problem is that the across flats measurement for this BSW/BSF size is 1.100" or 1 1/10" and you won't find that on a normal rule.

 

If you have access to a vernier or a digital caliper, you can measure in inches,

Edited May 10, 2010 by antarmike

[griff66]

across the flats measurement is taken , if u in uk machine mart is good source of cheap tools.

[markbg]

It could be 1 1/8" which is 28.575mm

 

1 1/16" is smaller than the 27mm you have tried (26.9875mm)

 

the only other contender is 1 3/16" which is bigger than the 30mm you have already tried (30.163mm)

 

so unless it is a BSF/ or BSW bolt it has to be 1 1/8" A/F.

 

If it is BSF/ BSW the only contender is 5/8"W, 11/16" BSF which is 27.94mm.

 

9/16"W, 5/8"BSF is too small at 25.76mm

and 11/16"W, 3/4"BSF is too big at 30.48mm

 

It has to be either an 1 1/8" A/F or an 5/8"W, 11/16" BSF Socket you need.

 

If it is a drain pug it could be a BSP thread, so it is likely to be a BSW, BSF size but the Fox experts will tell you.

 

or you could measure with a rule or a caliper....

 

Crikey thanks! Thats enough to go on - silly metric system means I just dont know anything about the imperial sizes - 1 1/8" sounds about right to me but Ill check BSW BSF as well

 

thanks again

[antarmike]

Crikey thanks! Thats enough to go on - silly metric system means I just dont know anything about the imperial sizes - 1 1/8" sounds about right to me but Ill check BSW BSF as well

 

thanks again

 

28mm will be quite easily available and this is only 0.002" bigger than the BSF size, and may be easier to find than the BSF exact size.

 

Out of interest 29mm is also a standard socket that is easy to find.( if you want to fill in gaps in your toolset.) Individual sockets can be bought from Cromwell Tools, and their own brand "Kennedy" has a good reputation.

Edited May 11, 2010 by antarmike

[antarmike]

across the flats measurement is taken , if u in uk machine mart is good source of cheap tools.

But only sets, not individual sockets...

[griff66]

unless a fox is metric unlike a ferret i would imagine if you own a fox buying a socket set and spanners would be a good move and like i mentioned machine mart sells a reasonable range of metric and a/f possibly whit and/or bsf as well , for not alot of dosh ( not compared to fuel at 125 p a :cool2:litre anyway!!!