Want info on this WRIGHT wrench.

[phillie]

Here I am on Saturday night in the tool forum. I guess it is my form of safe sex. Anyways I found this cool wrench.

One end is marked 9 16 OP. and 5/8 SAE and the other 1/2 OP. and 5/16 SAE. It is stamped WRIGHT P 3 0. The wrench is very crudly made. I could not find much info on WRIGHT except for their adjustable wrenches. I am not sure what the OP. stands for...opening??. It appears that the wrench would date back to the transitional period between OP and SAE. Can someone date this by knowing when SAE started? 

Thanks again
Namaste

[Papaw]

Don't see OP here, but here is Bus Haury's comment-

5 - Size Standard Markings
Note: In 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
AF    Initials: AF (used with size in inches of nut or bolt head i.e. I/2 AF)
Across Flats (British?)
Size as measured across the flat sides of nut or bolt head or actual wrench opening size
OC    Hex logo and initial C (used with size in inches of bolt diameter i.e. I/2 OC)
Hex Cap Screw
Found on older forged wrenches before 1920 standard want into effect (see note above)
SAE    Initials: SAE (used with size in inches of bolt diameter i.e. I/2 SAE)
Society of Automotive Engineers (fine threaded nuts and bolts)
Found on older forged wrenches before the 1929 standard want into effect (see note above)
USS    Initials: USS (used with size in inches of bolt diameter i.e. I/2 USS)
United States Standard.
Found on older forged wrenches before the 1929 standard want into effect (see note above)

[rusty]

The 'OP' most likely does stand for 'Opening', this is a pecularity that appears to be unique to Wright, and only for a brief period of time. Your wrench is not common, and is fairly old, likely from the 20's. The model is 'P3' , the '0' (zero) is a date code, but early Wright date codes are not certain enough to date it reliably , perhaps 1930. (Wright was only formed in 1927, you have a sample of their earliest production, which is why it's a bit crude looking..)

[lbgradwell]

Very cool; I've never seen one of those before...

[phillie]

Thanks guys...will proably put it up on E-Bay this week.