Wrench sizes from 1926 Service Manual

[Brian Z]

I am preparing to remove a rear leaf spring from our 1926 Studebaker roadster and am using a copy of the original service manual.
Tools required include No. 31 and 33 wrenches.
Can anyone tell me if there is a conversion chart or way to determine the equivalent standard size for these?
Are they metric?

[Chris Bamford]

Perhaps the numbers are not sizes per se, but factory tool numbers. 
 

Is there an illustration or description of factory tools in your manual?

[dictator27]

No conversion chart and they are not metric.

Just crawl under the car with your socket set "normal" wrenches will fit.

[mike6024]

This is a No. 31 Bonney wrench. But the sizes are actually 1/2 and 5/8. Does that sound about right? Is this wrench for spring shackle nuts?

 

 

[mike6024]

This is a No. 33 wrench and the sizes are actually 9/16 and 1/2.

 

Strange. Seems the 31 is 1/2 and 5/8, while the 33 is 1/2 and 9/16.

 

So if you have a bolt head and nut that are both 1/2.

[mike6024]

No. 34 wrench is 7/8 and 1 and 1/16

No. 37 wrench is 1 and 1/16 and 1 and 1/4

Edited November 18, 2021 by mike6024 (see edit history)