Automotive Measurement Tools

1. Six inch ruler: one inch is divided into sixteen equal parts. (Referred to as sixteenths). This measuring device is used for general measurements, not precision measuring.

2. Spark plug gapper: one of many varieties, spark plug slides around a tapered edge. C.C.W. from thin or narrow gap, to thick or wide gap. (Not the most accurate gapper.)

3. Measuring tape: measurers in inches or millimeters. Used for general measurement. Depending on the size of the tape, measurements can be made 10' to 100'. This type of measuring device can be used to measure wheel bases and other long measurements.

4. Metric bolt and nut gauge with wrench sized, and thread pitch: This gauge measures thread diameter length of bolt, (length does not include bolt head), wrench size, and the pitch of the bolt thread. (Explain thread pitch on chalk board, pitch angles can be pound or the gauge.)

5. Six inch steel rule with T slide: divided into 32 equal parts and 64 equal parts (thirty-seconds and sixty fourths). More accurate than a ruler divided into 16ths, but still used for general information measurements. (Demonstrate how T slide can make depth measurements or used as a measurement stop.

6. Wire type spark plug gapper: Each wire is a specific diameter. The wire slide past the spark plug electrodes. This is one of the more accurate spark plug measuring devices.

7. Feeler gauge: flat precision ground pieces of steel - very accurate. Can be used to measure a specific distance between surfaces or automotive parts. Measures in thousandths of an inch.

8. Dept Micrometer: measures in thousandths of an inch. This tool can measure a specific depth when set on a machined surface. (Draw demo on board.)

9. Inside micrometer: used to measure inside diameters (inside part of a circle) in thousandths of a inch. Its purpose is to check oversize, taper, and out-of-round (show on board).

10. Dial indicator and fixture assembly: Can be attached to the engine or transmission. The indicator or dial put against the movable part. Dial will register the amount of distance the movable part can move. (Measures in thousandths)

11. Vernier caliper or dial caliper: Very accurate instrument. Can measure inside and outside. (Measures in thousandths.)

12. Outside micrometer: The auto industry uses micrometers that graduate from one inch to five inches. (0.1" example measures in thousands) Used to measure outside diameter of pistons and crankshafts. Very accurate measurement. (Used in engine rebuilding and engine maching.)