Bridge City Tool Works - BP18 Bevel Protractor, Signature Series 1992 . Condition is Used. Shipped with USPS Priority Mail. There are a few stains. All markings are clear since they are photochemically etched into the hardened steel surface. All edges of the protractor plate are ground square to with in 0.002 inches. All parallel edges are with in 0.001 inches. The protractor uses an 18 inch indicator arm which is particularly useful in setting up table and... radial arm saw miter gages. The indicator arm is locked in position by two knurled brass knobs making the tool rigid with booth knobs tight.