[12   Spindle Length |  Base: 3-1  & 2   Length |  3-3  & 16   Width]

The Starrett 257C full-sized surface gauge has a 12”/300 mm spindle mounted onto a hardened steel base, with a 8.5”/216 mm scriber for accurately scribing lines, transferring measurements, and probing surfaces in inspection work.

The included scriber is 8.5”/216 mm in length and 0.16”/4 mm in diameter, and is held to the spindle by a sliding snug with a knurled, ring-type lock nut for secure positioning. The 12”/300 mm spindle is 0.38”/9.5 mm in diameter. The steel base is hardened, ground, and lapped for a smooth, flat surface, and measures 3.5”/90 mm by 3.19”/80 mm. Four frictionally held gauge pins in the base can be pushed down and referenced against the edge of a surface plate or T-slot for linear work. The satin chrome finish resists rust and is glare-free.

Surface gauges, sometimes referred to as gages, are a tool for machinists and toolmakers to mark lines on a workpiece, transfer measurements from one workpiece to another, and for probing surfaces in inspection work. The scriber is held by a snug that travels on a vertical column (also called the spindle), and may be locked into position by a screw clamp. Surface gauges are typically used in manufacturing, machining, and mechanical engineering.

The L.S. Starrett Company manufactures precision measuring tools, metrology and testing equipment, and saw blade products. The company was founded in 1880 and is headquartered in Athol, MA.