I have a Bonney OE-OE wrench with WE1618 stamped on one side.  It also has 1/2 stamped on one end, and 9/16 stamped on the other end.  However, the opening on the "9/16" end is 1" wide, and the opening on the "1/2" end is 15/16".  Wondsering if anyone else has ever seen this.

Its an oldie. My Williams wrenches are the same.
1/2" means a 1/2" bolt shaft, but the big square head of said bolt, that the wrench goes on?
Is 15/16".

They used to mark all wrenches this way. But it turned out be easier for mechanics to remember to just  mark them the size of the bolt's head. 
  A 1/2" wrench size now, fits a 5/16 bolt.

I don't really think either are any easier, one system over the other,
  but everyone got together and decided with their dollars, buying the wrenches marked for the head size instead of the shaft size.
  yours Scott

QuoteIn the United States prior to 1929 the sizes stamped on wrenches usually referred to the diameter of the bolt not the actual opening size. Thus a wrench stamped ½ U. S. would actually have a 7/8" wrench opening size as a nut for a ½" diameter U. S. Standard bolt would measure 13/16" across the flats and allowing for 1/16 clearance would require a 7/8" wrench opening. This same size wrench would also fit nuts for 5/8" hex cap screw and bolt and nuts for 9/16" S.A.E Standard Cap Screws and thus would be marked ½ U.S, 5/8 Hex Cap, and 9/16 SAE. Carl Bolt's website page on tool standards pictures 17 wrenches with 19 different identifications and sizes all marked 1/2"! This could get pretty confusing so circa 1929 the American Engineering Standards Committee specified that wrenches should be marked with the actual width across the flats of the nut or bolt head they would fit

From The Wrenching News-  http://www.wrenchingnews.com/wrench-logos/logos-page-1.html

>OE-OE wrench with WE1618

Incidently, Bonney's part number system was somewhat elegant, the 4 digit number also tells you the wrench size.

1618 -> 16;18 ->  16/32 = 1/2 ; 18/32 = 9/16

Thanks for the input! It just goes to show that you are never to old to learn something new.  I have just inherited a collection of 500-600 wrenches (all USA), so am glad I found this forum.  I will probably have a bunch of questions.

Thanks again!

Quote from: runder on February 18, 2013, 09:52:00 PM
Thanks for the input! It just goes to show that you are never to old to learn something new.  I have just inherited a collection of 500-600 wrenches (all USA), so am glad I found this forum.  I will probably have a bunch of questions.

Thanks again!

That'll keep you busy.

Welcome!! Please show us photos.  It is fun to see the collections of others.

Welcome and yes--we need pictures!!!!

Yes, the B-man also insists on seeing pictures....especially of Bonney tools!