PRECISION MEASURMENT

Vocabulary 1.British imperial (U.S.) Systems 11.) Metric system 12.)inside micrometer 3.Psi 13.)dial caliper 4.Foot- pounds & Newton meters 14.)dial indicator 5.Plastigage 15.)depth micrometer 6.O.D. 16.)dial bore gauge 7.I.D. 17. )feeler gauge 8.Micrometer 18.)wire gauge 9.Thimble 19.)thread pitch gauge 10.sleeve 20.)straight edge

Precision measurement is needed to: Mass produce products ( assembly line) Mass produce products ( assembly line) Interchangeability of parts Interchangeability of parts Function of assemblies ( oil clearance - ect) Function of assemblies ( oil clearance - ect) Correct fit of assembly. Correct fit of assembly.

In one sixteenth of an inch (1/16) there are sixty two and one half thousandths (.0625) Fractions are not accurate enough for the automotive industry. Every part on your vehicle is manufactured using precision equipment capable of accuracy within thousandths of an inch.

Decimal system One’s Tenth’s Hundredth'sThousandth’s

4 place decimal One’sTen’sHundred’sThousandth’s Ten Thousandth’s

Precision Measuring Tools

Outside Micrometer Outside mic’s come in one inch increments ( ) Can measure to the ten thousandth of an inch. Use three scales to get the reading.

Outside Micrometer

Outside mic set standards

Dial Caliper Measures 0” – 6” O.D. I.D. & depth with.001 accuracy

Dial indicator Checks for movement.001 accuracy

Snap Gauge (set) Can a snap gauge give you a dimension?

Dial Bore gauge Best tool to check engine cylinder Bore accuracy

Feeler gauge Used to check ________.001 accuracy

Spark plug gap gauge

Thread pitch gauge Metric & std.

Straight edge Accuracy along length Always used with feeler gauge

Torque wrench Foot LBS. In LBS. & Newton Meters How many Ft. lbs. should wheel lugs be?

Plasti-gauge Plasti-gauge crushed on journal Indicated clearance crankshaft

Parts of an outside Mic spindle Anvil - carbide Frame Sleeve or barrel Spindle lock Thimble Ratchet

How to Read a Micrometer

Total :

Try these Mic’s

Micrometer Practice Read Thimble second Read sleeve first total

.125

.130

How to read a Dial Caliper

.100 Read first Read dial second Total.100

.050

.739

1.000 Dial =.010 Total 1.010

This thing was actually used to BBQ!