Incra guarantees their new 90° and 45° try squares not to deviate by more than .001" from nominal at any point along their blades, inside and out—close enough for government work, and any other kind for that matter. Their innovative one-piece design is milled from solid 1/4" aluminum stock, with no joints to introduce error or come loose down the road, even if dropped. Hard anodized surfaces are tougher than brass, and tarnish-proof as well. Each square stands unaided on handle or blade, and the miter squares, placed with blade & handle down on a flat surface, also offer a reliable 90° reference along the outside of the handle.