These are Starrett's top-of-the-line combination squares. Useful for joint layout or machine set-up and as depth, height or marking gauges, they feature long-wearing forged steel heads paired with hardened steel rules with photo-engraved scales. The reversible rules have a satin-chrome finish that reduces glare and resists rust, while the precisely machined heads have a smooth enamel finish. Except for the 4" size, all come with a steel scribing pin and a built-in level vial for determining level or plumb.
The 4", 6" and 150mm models are square to within ±0.001" over the full rule length; 12" and 300mm sizes are square to within ±0.002". Imperial rules are graduated in the 4R style (with increments in 8ths, 16ths, 32nds and 64ths); metric rules are graduated in millimetres and half-millimetres on both faces. The 4" rules are 1/16" thick by 5/8" wide; the 6" and 150mm rules are 0.080" thick by 3/4"/19mm wide; the 12" and 300mm rules are 0.090" thick by 1"/25mm wide. Rules are straight and parallel within 0.001" per foot.
A protractor head and center-finding head are offered separately.
Versatile, classic designs. Made in USA.