Precision Measurement for Machinists - Online
Lesson Outline

Module 1: Viewing the Part Print and Understanding Dimension Information [ Top ]

After completing this module the operator will be able to identify and explain:

  1. Multi-view print and explain its relationship to part features
  2. Workpiece features and their locations on a print
  3. A half section and full section view
  4. A detail view
  5. An auxiliary view
  6. A center line
  7. Both object lines and hidden lines
  8. An extension line
  9. A dimension line
  10. Leader line
  11. A cutting plane line and its reference notation
  12. A line
  13. A datum feature
  14. A coaxial and coplanar datum feature
  15. A datum target feature

Module 2: Reading and Interpreting Symbols on a Part Print [ Top ]

After completing this module the operator will be able to identify and explain:

  1. DIA, D, Ø
  2. R, RIA, RAD
  3. TIR, FIR, FIM
  4. TYP, 2X, 3X
  5. MAX
  6. MIN
  7. C, CFR, CHAM
  8. Surface Finish Symbol
  9. Counter Bore, Counter Sink, Depth Symbols

Module 3: The Title Block and Tolerances [ Top ]

After completing this module the operator will be able to:

  1. Identify the Title Block
  2. Identify the Notes Area
  3. Explain Nominal Dimension
  4. Identify Basic Dimensions
  5. Identify Reference Dimensions
  6. Datum vs. Chain Dimensioning
  7. Find Missing Dimensions

Module 4: Fundamentals of the Inch and Metric Systems [ Top ]

After completing this module the operator will be able to identify and explain:

  1. Inch and Metric System principles
  2. Elements of the Inch System
  3. Elements of the Metric System
  4. Visualize dimensions and estimate sizes
  5. The factors used to convert inch and metric measurements

Module 5: Essential Geometry for Machinists [ Top ]

After completing this module the operator will be able to identify and explain:

  1. The practical benefits of GDT in manufacturing
  2. Point
  3. Line
  4. Plane
  5. Two dimensional coordinate grid
  6. Three dimensional coordinate grid
  7. Origin of coordinate grid
  8. Positive and negative coordinates
  9. Circle, circumference, diameter and radius
  10. Cylinder
  11. Parallelism
  12. Perpendicularity

Module 6: Fundamentals of Geometric Dimensions and Tolerances [ Top ]

After completing this module the operator will be able to identify and explain:

  1. The relationship between form and function
  2. Form
  3. Orientation
  4. Location
  5. Runout
  6. Profile
  7. Feature Control Frame
  8. ISO, ANSI, and ASME

Module 7: Geometric Position Tolerances [ Top ]

After completing this module the operator will be able to identify and explain:

  1. True Position tolerancing
  2. True Position Symbol
  3. Coordinate location tolerancing
  4. Square versus round tolerance zones
  5. True positioning versus "coordinate" location
  6. Location tolerance control over form of part features

Module 8: Material Condition Modifiers and the Feature Control Frame [ Top ]

After completing this module the operator will be able to explain:

  1. Purpose of Condition modifiers
  2. Maximum Material Condition (MMC)
  3. Least Material Condition (LMC)
  4. Regardless of Feature Size (RFS)
  5. Compartments within a Feature Control Frame

Module 9: Size Tolerances and Form Control [ Top ]

After completing this module the operator will be able to explain:

  1. Where size tolerances apply on a feature
  2. Boundary of Perfect Form
  3. Functional Gages

Module 10: Measuring Geometric Tolerances [ Top ]

After completing this module the operator will be able to explain:

  1. Limits of Functional gages
  2. Open setup inspection
  3. Optical comparator
  4. Air gages
  5. Coordinate measuring machine (CMM)

Module 11: Datums [ Top ]

After completing this module the operator will be able to explain:

  1. Why Datums are used for measuring Geometric dimensions
  2. Simulated Datums
  3. Datum Features
  4. Datums
  5. Datums for Cylindrical features

Module 12: Fixturing Workpieces and Establishing Datums [ Top ]

After completing this module the operator will be able to explain:

  1. The correct order to establish Datums, given a Feature Control Frame callout
  2. The correct number of points of contact when establishing Datums, based on the type of feature and the Datum order
  3. Establishing Datums for measurement, including flat surfaces, linear elements along a cylindrical feature, rotational axes, slots or tabs

Module 13: Bonus Tolerance [ Top ]

After completing this module the operator will be able to:

  1. Explain Bonus Tolerance concept
  2. Explain how Bonus Tolerances are possible based on material condition modifiers
  3. Given a part print and workpiece, calculate a bonus tolerance
  4. State the formula used to calculate bonus tolerances
  5. Calculate the MMC size of a feature
  6. Measure the feature on a workpiece
  7. Calculate the bonus tolerance based on the previous calculations
  8. Calculate additional bonus tolerance from the material condition of Datum features

Module 14: Adding and Subtracting Signed Numbers [ Top ]

After completing this module the operator will be able to:

  1. Explain the rules for adding signed numbers
  2. Explain the rules for subtracting signed numbers
  3. Calculate with signed numbers

Module 15: The Principles of Metric and Inch Measurement [ Top ]

After completing this module the operator will be able to:

  1. Explain the elements of Metric measuring system
    1. Identify the thousandths, hundredths, tenths and whole millimeter places in a dimensional value
    2. Relate the centimeter and millimeter to the inch
    3. Estimate Metric measurements based on relations to the inch
    4. Locate Centimeter divisions on a scale
    5. Locate Millimeter divisions
  1. Locate and identify the following features on an Inch dimension:
    1. One inch, decimals, fractions
    2. When fractions and decimals are used
    3. Half, quarter, eighths, sixteenths, thirty seconds and sixty fourths
    4. Thousandths, hundredths, and tenths of an inch and how they relate
    5. How decimals and fractions differ and converting between them

Module 16: Converting and Rounding Decimal and Tolerance Limit Values [ Top ]

After completing this module the operator will be able to:

  1. Convert between the inch and metric systems
  2. Round to the correct number of decimal places
  3. Calculate Tolerance limits
  4. Run Tolerance limits
  5. Perform shop math calculations: add, subtract, multiply, and divide

Module 17: Avoiding Errors in Performing and Expressing Calculations [ Top ]

After completing this module the operator will be able to:

  1. Use mental estimation before calculation
  2. Avoid Transposition of numbers
  3. Avoid mistakes when entering values
  4. Communicate values correctly in inch and metric

Module 18: Quality Control while Measuring Parts [ Top ]

After completing this module the operator will be able to explain factors of:

  1. Cleanliness
  2. Temperature
  3. Gage accuracy
  4. Gauge setting
  5. Workpiece Deformation
  6. Gage deformation
  7. Proper measuring technique

Module 19: Using The Steel Rule [ Top ]

After completing this module the operator will be able to:

  1. Explain tolerances that allow the use of a Steel Rule
  2. Locate the smallest measurement = to .010 or 1/64, or .5 mm
  3. Identify the sizes of rules
  4. Explain dual dimensioned Steel Rules
  5. Explain the three causes of errors: Worn edge, rule not parallel, parallax error
  6. Count whole units to feature end point
  7. Count remaining unit spaces to end point
  8. Total the measurement
  9. Write down the value correctly for the feature measured
  10. Explain the care and handling of the steel rule

Module 20: Identifying the Features and Types of Micrometers [ Top ]

After completing this module the operator will be able to:

  1. Identify major parts of the inch micrometer
  2. Locate the baseline and zero point
  3. Locate 100 thousandths division lines
  4. Locate the 25, 50, 75 thousandths lines
  5. Locate the thimble and thousandths division lines
  6. Locate whole and half mm divisions on metric micrometer
  7. Locate thimble scale on metric Micrometer
  8. Explain OD & ID
  9. Explain Depth
  10. Locate and explain a Thread micrometer
  11. Identify Special mics

Module 21: Use and Care of a Micrometer [ Top ]

After completing this module the operator will be able to:

  1. Clean Workpiece and Micrometer
  2. Rapidly open and close the micrometer
  3. Identify different ranges of micrometers
  4. Close with proper tension a micrometer using a friction thimble or ratchet stop
  5. Close with proper tension a micrometer which has a friction knob
  6. Check zeroing of micrometer
  7. Explain thimble rotation and resulting spindle travel
  8. Hold the micrometer properly
  9. Properly fit the micrometer to the workpiece to read the required dimension
  10. Changes in feel for round of cylindrical workpieces (reduce pressure to avoid compression of the piece)

Module 22: Reading and Totaling Micrometer Measurements [ Top ]

After completing this module the operator will be able to:

  1. Determine whole inch spaces
  2. Determine 100 thousandths spaces
  3. Determine 50 thousandths spaces
  4. Determine number of the 25 thousandths
  5. Write down values starting with micrometer size
  6. Align decimal points and total
  7. Identify the vernier scale and the tenth
  8. Read the vernier scale correctly
  9. Correctly total a measurement using a vernier instrument
  10. Determine whole mm
  11. Determine half mm spaces
  12. Determine hundredths on sleeve
  13. Locate vernier scale on metric mic

Module 23: Repeatability and the 10 to 1 Rule [ Top ]

After completing this module the operator will be able to explain:

  1. Ten-to-one rule
  2. How to select measuring instruments
  3. The Concept of Repeatability

Module 24: Digital Micrometers [ Top ]

After completing this module the operator will be able to:

  1. Identify the types of digital micrometers
  2. Locate the features of mechanical digital mics
  3. Measure with a mechanical digital mic
  4. Read the measurement
  5. Explain the features of electronic digital mics
  6. Measure with an electronic digital mic
  7. Read the electronic measurement
  8. Store and maintaining the instrument

Module 25: Caliper Measurements and Components [ Top ]

After completing this module the operator will be able to:

  1. Find lengths or outside diameters using the Outside Jaws
  2. Find inside diameters using the caliper blades
  3. Find recesses and depths using the depth rod
  4. Locate and explain the use of the Beam
  5. Locate and explain the use of the Outside and Inside Jaws
  6. Locate and explain use of the Depth Rod
  7. Locate and explain the use of the Slide
  8. Locate and explain the use of the Dial
  9. Locate and explain the use of the Vernier scale
  10. Explain the relationship between the divisions on the Beam and the Vernier scales
  11. Explain the "offset" jaw caliper and its two vernier scales

Module 26: Measuring Workpiece Features with a Dial Caliper [ Top ]

After completing this module the operator will be able to:

  1. Check the calipers for proper adjustment and operation
  2. Clean the workpiece and calipers, and fit the calipers to the workpiece
  3. Apply the proper pressure during the measurement
  4. Use the Knife Edges properly for measuring grooves
  5. Rotate workpiece to find true diameter
  6. Read the number of whole inches on the Beam
  7. Read the number of hundreds of thousandths on the Beam
  8. Read the dial to determine the number of thousandths
  9. Total the measurement
  10. On a Metric Caliper, determine if centimeters or millimeters are used on the Beam
  11. Read the number of Beam units as millimeters
  12. Read the number of hundredths of a millimeter on the dial
  13. Add the readings to determine the measurement
  14. Clean and store the calipers when finished

Module 27: Measuring with Vernier and Digital Calipers [ Top ]

After completing this module the operator will be able to:

  1. Explain the process of locating the matching lines on vernier scales
  2. Explain the beam and vernier divisions on a vernier caliper
  3. Locate the start point of the measurement
  4. Make an accurate measurement using an inch vernier caliper
  5. Locate the scales and divisions on an inch/metric caliper
  6. Using the metric scale, make an accurate measurement
  7. Describe how to determine the match line as it relates to the relative location to the tolerance allowed
  8. Locate and identify the features of a digital calipers
  9. Explain the auto-shutoff feature
  10. Convert between metric and inch measurements
  11. Zero the digital caliper at any point
  12. Read measurements with signed numbers on a digital caliper

Module 28: Go, No-Go Gages [ Top ]

After completing this module the operator will be able to:

  1. Identify and explain the use of Go, No-Go gages
  2. Explain the components of, and properly use, snap gages
  3. Explain the use of Functional gages
  4. Explain and properly use Plug and Pin gages
  5. Explain and properly use Ring gages
  6. Explain what to do if a feature fails a Go, No-Go test

Module 29: Characteristics of Surface Finish [ Top ]

After completing this module the operator will be able to:

  1. Explain the characteristic of Roughness
  2. Explain the characteristic of Waviness
  3. Explain the characteristic of Lay
  4. Explain the characteristic of Flaws

Module 30: Identify Units of measure for Surface Finish [ Top ]

After completing this module the operator will be able to:

  1. Explain Profile and Nominal Profile
  2. Identify and explain Microinches and Microns
  3. Identify peaks and valleys
  4. Identify and explain Ra and Aa
  5. Identify and explain the surface finish symbol and its components

Module 31: Surface Finish Comparison Gages [ Top ]

After completing this module the operator will be able to:

  1. Explain Comparison Gages
  2. Identify the Range of Comparison Gages
  3. Use a Comparison Gages to Measure Surface Finish

Module 32: Using Analog and Digital Profilometers [ Top ]

After completing this module the operator will be able to:

  1. Components of analog profilometers
  2. Explain cutoff
  3. Range of analog profilometers
  4. Set up and measure with analog profilometers
  5. Set up and measure with digital profilometers

Module 33: The Portable Surface Roughness Gage [ Top ]

After completing this module the operator will be able to:

  1. Uses for the Roughness Gage
  2. Identify components of the gage
  3. Calibrate the gage
  4. Measure Workpiece roughness

Module 34: The Parts of a Thread [ Top ]

After completing this module the operator will be able to explain:

  1. Thread Crest
  2. Thread Root
  3. Pitch versus Pitch Diameter
  4. Lead of a thread
  5. Major Diameter of OD and ID threads
  6. Pitch Diameter
  7. Minor Diameter of OD and ID threads
  8. How Geometric Tolerances apply

Module 35: Standard Thread Notation [ Top ]

After completing this module the operator will be able to:

  1. Explain the Unified Inch Screw standard
  2. Identify the UNC, UNF, UNEF, UNJC, NPT and ACME designations
  3. Locate Major Diameter notation and actual class size
  4. Locating the tolerances of Pitch Diameters on a chart
  5. Identifying the Threads Per Inch
  6. Calculate the Pitch from the TPI value
  7. Explain Class of Fit and Hand designations
  8. Identify "M" (metric) symbol
  9. Calculate the nominal major diameter in millimeters
  10. Explain the Pitch in a the metric thread notation
  11. Metric Coarse Threads: Look up and read the thread Pitch from a chart of metric thread standard dimensions
  12. Metric Fine Threads: Read the thread Pitch behind the "times sign"
  13. Describe the class of fit and g & h allowance notations
  14. State whether internal or external threads
  15. Read the Pitch Diameter if shown

Module 36: Methods of Measuring Threads [ Top ]

After completing this module the operator will be able to:

  1. Explain the steps involved in thread measurement
  2. Clean threaded features and measuring instruments
  3. Explain the features that a GO gage is checking on an OD thread
  4. Based on print specifications, select the measuring instrument
  5. Use a Go, No-Go Snap gage for Major Diameter and Pitch Diameter
  6. Detecting no-go conditions for inch and metric gages
  7. Use a go, no-go Plug gage for ID threads
  8. Correctly use Ring gages for OD threads
  9. Measure Pitch Diameter using a Pitch Micrometer
  10. Use a Tri-Roll gage to measure Pitch Diameter
  11. Identify the parts of a tri-roll gage
  12. The effect of multi-thread rolls
  13. Read the values on the face of the dial indicator
  14. Locate the tolerance limit dimensions in reference materials
  15. Identify the tolerance limit represented by a Master gage
  16. Place the master in the gage
  17. Set the tolerance limit on the dial face (zero the dial)
  18. Calculate and mark the other tolerance limit on the dial
  19. Note the full rotations when Mastering the gage
  20. Place a workpiece into the gage
  21. Complete a measurement at several locations
  22. Visually check thread quality and finish
  23. Check thread crests and identify faulty conditions

Module 37: Using Optical and Video Comparators [ Top ]

After completing this module the operator will be able to:

  1. Identify the components of an optical comparator with digital display
  2. Identify the axes of motion
  3. Identify the rotational axis of the table
  4. Explain the divisions on the screen grid
  5. Explain how the grid divisions change with changes in magnification
  6. Mount a threaded workpiece to the stage
  7. Set the angle of the table to the Helix Angle
  8. Focus the shadow
  9. Complete a root radius measurement
  10. Complete a feature length measurement
  11. Complete a angle measurement
  12. Measure a radius by matching to the grid arcs
  13. Identify Gage Charts and their magnification settings
  14. Read the limit lines scribed on a Gage Chart
  15. Identify the components of a video comparator/vision system
  16. Focus workpiece features using a vision system
  17. Measure the features of a part using a vision system
  18. Calculate the diameter of a hole using a vision system
  19. Measure an angle using a vision system
  20. Measure a radius/arc using a vision system

Module 38: Open Setup Inspection and the use of Dial Indicators [ Top ]

After completing this module the operator will be able to:

  1. Identify components of dial and test indicators
  2. Interpret the reading on a dial face
  3. Explain the difference between balance dials and continuous dials
  4. Select the correct contact point for a dial indicator
  5. Set up an indicator properly for measurement
  6. Select the correct indicator (range, inch/metric)
  7. Explain typical applications of indicators in inspection

Module 39: Surface Plates and Holding Devices for Open Inspection [ Top ]

After completing this module the operator will be able to:

  1. Describe surface plates and explain when they are used
  2. Explain how to work with surface plates to avoid damaging them
  3. Fixture workpieces using the appropriate equipment
  4. Fixture workpieces by the proper feature for measurement
  5. Identify and use V-blocks
  6. Identify and use a Tri-Roll
  7. Explain Coaxial datum features
  8. Identify and use Parallel bars
  9. Identify and use Gage blocks for workpiece fixturing

Module 40: Using Gage Blocks for Open Inspection [ Top ]

After completing this module the operator will be able to:

  1. Describe uses of gage blocks
  2. Identify a typical set of shop-grade gage blocks
  3. Explain how to select gage blocks for a given dimension
  4. Explain how to properly clean and wring gage blocks

Module 41: Fundamentals of Height Gages [ Top ]

After completing this module the operator will be able to:

  1. Identify the components of mechanical height gages
  2. Explain the types of workpiece contact devices: test indicators, depth rod, scriber
  3. Perform rough and fine adjustment methods
  4. Read vernier scales, dials, and digital readouts on height gages

Module 42: Measuring with Cadillac and Comparator Height Gages [ Top ]

After completing this module the operator will be able to:

  1. Locate components of a Cadillac Master height gage
  2. Explain cautions about using the gage
  3. Perform a typical measurement sequence
  4. Read the gage
  5. Explain the Comparator gage
  6. Set the limits of the Comparator gage with gage blocks
  7. Sweep a workpiece

Module 43: Measuring with Electronic Height Gages [ Top ]

After completing this module the operator will be able to:

  1. Explain components of a digital height gages
  2. Locate Data ports and slide control switches
  3. Complete probe replacement
  4. Explain probe-tip offset compensation for various measurements
  5. Use gage blocks to set tip offset
  6. Perform a typical measurement

Module 44: Fundamentals of Coordinate Measuring Machines [ Top ]

After completing this module the operator will be able to:

  1. Identify the types of CMMs found in shops
  2. Explain the advantages of a CMM
  3. Identify the basic components of a CMM
  4. Identify the axes of motion
  5. Locate the Ways and their need for cleanliness
  6. Locate the Axis Control Switches and explain their operation
  7. Locate and explain the Manual Axis Controls
  8. Locate and explain the features of the Probe and Probe Tip
  9. Explain the use of an Indexable head
  10. Explain the purpose of the Computer
  11. Locate the Icons and their purpose

Module 45: Preparing the CMM for Measurement [ Top ]

After completing this module the operator will be able to:

  1. Explain when it is necessary to HOME the CMM
  2. Locate the Surface Plate and its mounting holes
  3. Locate and explain the purpose of the Qualification Sphere
  4. Clean the Surface Plate
  5. Prepare the workpiece for measurement
  6. Locate the piece and align a major axis to a CMM axis
  7. Clamp the piece correctly
  8. Locate and explain the coordinate display
  9. Locate the origin and datums of a feature
  10. Explain why the grid system is aligned to the origin of the features
  11. Explain when a probe tip must be changed
  12. Remove and replace a probe tip using the correct wrench
  13. Explain why the new tip must be qualified
  14. Start the Qualification process on the computer
  15. Explain when Multi-tip or Single Tip is to be used
  16. Move the probe in all three axes
  17. Properly touch-off the probe on the qualification sphere
  18. Explain the screen display and delete a hit
  19. Click DONE and explain the measured diameter value
  20. Locate and explain Standard Deviation values
  21. Locate and explain the Status Line values

Module 46: Aligning the CMM Coordinate System [ Top ]

After completing this module the operator will be able to:

  1. Explain the auto-naming process of features and datums
  2. Clear any existing auto named features
  3. Identify stored measurement sequences from the file list
  4. Check the Status Line to confirm Alignment status
  5. Perform a CLEAR ALIGNMENT sequence.
  6. Locate the datums assigned to the features to be measured
  7. Use the PLANE function to locate a datum surface
  8. Auto-name the Plane and check standard deviation
  9. Explain what to do when Standard Deviation is incorrect
  10. Use the LINE function to locate a datum and auto-name it
  11. Use the CIRCLE function to locate a hole and auto-name it
  12. Complete an alignment process using the assigned datums

Module 47: Common Measurement Procedures using a CMM [ Top ]

After completing this module the operator will be able to:

  1. Explain and select a TRUE POSITION measurement sequence
  2. Touch-off a hole to find True Position
  3. Set the screen display to True Position MMC
  4. Locate and enter the Nominal print coordinates of X and Y
  5. Locate and enter the Nominal diameter value
  6. Locate and enter the Upper and Lower tolerance limits
  7. Locate and explain the True Position measured values
  8. Complete the sequence on other features making adjustments to the nominal values as required
  9. Explain and select an ANGLES measurement sequence
  10. Use a line-to-line sequence
  11. Touch-off the first line feature in the correct direction
  12. Touch-off the second line feature in the correct direction
  13. Complete the sequence and display the correct angle and deviation
  14. Explain and select a PERPENDICULARITY measurement sequence
  15. Use a Bore / Plane sequence
  16. Touch-off circles within the bore at two locations
  17. Recall the named Plane
  18. Complete the sequence and display the correct value and standard deviation