I have about a dozen things that are supposed to be square. Half of them are not!
I trust my Post triangle and my 1-2-3 blocks. My old Bridge City dovetail gauge is square and the pair of aluminum red clamping angles seem to be good. Old Marples try-square is pretty close as well as the Chinese pattern square.
All three of my multi-squares are off. Ironic, the plastic one is the best. My igauge engineers square is close but not dead on. General digital protractor off a LOT. ( .4 degrees) Combo square I did not expect ( zinc head, not iron). I was able to hammer my framing square to be pretty close.
That explains why my shooting board and Lyon are not as perfect as I want and my TS is worse. No good to measure 5 corners when your gauge is off! Sigh, I guess that means I have to spend real money for a couple more tools, though Post triangles may be the best bet.
I trust my Post triangle and my 1-2-3 blocks. My old Bridge City dovetail gauge is square and the pair of aluminum red clamping angles seem to be good. Old Marples try-square is pretty close as well as the Chinese pattern square.
All three of my multi-squares are off. Ironic, the plastic one is the best. My igauge engineers square is close but not dead on. General digital protractor off a LOT. ( .4 degrees) Combo square I did not expect ( zinc head, not iron). I was able to hammer my framing square to be pretty close.
That explains why my shooting board and Lyon are not as perfect as I want and my TS is worse. No good to measure 5 corners when your gauge is off! Sigh, I guess that means I have to spend real money for a couple more tools, though Post triangles may be the best bet.