LO 5-3 Identify and describe common instruments and techniques to make linear precision measurements

Gauge Blocks
Gauge blocks are precision-machined pieces of aluminum or steel used to determine whether a dimension’s thickness or width is within specification FIGURE 24. For example, injector height, on some injectors, is adjusted with gauge blocks to obtain a safe plunger travel distance FIGURE 25. The thickness or width of the gauge block measures small distances to adjust the clearances of components or to check for excessive wear between parts that are under 6" (150 mm). They can also be used to check the size of a piston ring groove, check the accuracy of a micrometer, or calibrate a dial bore gauge. Gauge block dimensions are usually stamped on the gauge as either a metric or an imperial measurement.

FIGURE 05-24: Notches in the end of the camshafts are aligned to be parallel using this gauge block.

FIGURE 05-25: A gauge block used to adjust the height of an electronic unit injector (EUI).