This is a protractor head by Sawyer Tool Mfg Co, Fitchburg Mass USA. The number '25' is stamped below the vial on both parts, I don't know if this is a model number or something else.
I'm guessing this head will likely fit a variety of older USA made rules. It definitely fits on a Union Tool company combination rule I have, but it does not fit on a beefier English made Starrett rule. As far as I can tell the Union Tools rule is 2mm thick while the Starrett is 2.2mm.
sawyer1.jpgsawyer2.jpgsawyer3.jpgsawyer4.jpg
I'm guessing this head will likely fit a variety of older USA made rules. It definitely fits on a Union Tool company combination rule I have, but it does not fit on a beefier English made Starrett rule. As far as I can tell the Union Tools rule is 2mm thick while the Starrett is 2.2mm.
sawyer1.jpgsawyer2.jpgsawyer3.jpgsawyer4.jpg
QLD Sawyer Tools Protractor Head for adjustable square
