Starrett 120-12 Dial Calliper, Stainless Steel, White Face, 0-12" Range, +/-0.001" Accuracy, 0.001" Resolution

The Starrett dial measuring knight has every 0.100" sharp black gradations on the anti-glare, satin stainless steel bar and graduations on the dial every 0.001". A full turn of the dial corresponds to 0.100 inches. These calipers have knife edge contacts for measuring both the inner dimensions (ID) and the outer dimensions (OD). The knife edge contacts can be used to draw parallel lines on the workpiece. This measuring tube can be used with one hand by operating the fine adjustment roller with the thumb. The locking locks the pointer bezel and holds the sliding jaw in place. Unlike many calipers, the depth bar is integrated into the frame of the caliper, unlike many calipers that offer one or no removable depth bar. The hardened stainless steel components, including the rod, measuring surfaces, rack, gears and depth bar, provide corrosion resistance, increased accuracy and long service life. The anti-play control with positive split gear provides increased accuracy over standard transmission configurations. Game is the distance between the pasted gear teeth in the caliper controls, which prevents jamming of the gear teeth. Due to the lack of precision provided by the increased play between gears, it is undesirable to have a lot of play. Certain gear designs can minimize or eliminate the backlash. Split gear systems actually split the gear into two gears, each half the thickness of the original gearbox. One of these gears is then attached to the shaft while the other gear is allowed to rotate. The unlocking gear is connected to coil springs that rotate it until all the clearance in the control system is eliminated. The rack and pinion teeth point downwards so that foreign objects do not clog the transmission processes. This prevents measurement errors where metal chips could interfere with the proper operation of the measuring plate board.