Vintage L.S. Starrett No. 490 12” Bevel Protractor No. 4 Rule Machinist Tool For Sale

Vintage L.S. Starrett No. 490 reversible bevel protractor fitted with a 12-inch Starrett No. 4 graduated hardened steel rule. Made in Athol, Massachusetts, USA, this precision measuring tool was designed for machinists, toolmakers, patternmakers, and other skilled tradespeople who needed to measure, transfer, or lay out angles accurately.The semicircular head features clearly engraved opposing 0–180-degree scales, allowing angles to be read from either direction. Its adjustable locking mechanism secures the rule at the selected angle, while the built-in spirit level adds another useful reference for setup and alignment work. The No. 4 rule has fine machinist graduations and is marked STARRETT and HARDENED.Founded in 1880 by Laroy S. Starrett, the L.S. Starrett Company became one of America’s most respected manufacturers of precision measuring tools. Earlier American-made Starrett instruments remain especially desirable because they combine practical shop use with the craftsmanship and substantial construction associated with traditional machinist tools.This is an appealing working-shop collectible with an honest aged surface, black-finished cast head, brass-toned adjustment hardware, and visible evidence of years of skilled use. It would be equally appropriate for a machinist’s bench, an industrial tool collection, or display in a workshop.Includes the Starrett No. 490 protractor head and attached 12-inch No. 4 rule shown in the photographs. No case or additional combination-square heads are included.