1. LAYOUT TOOLS AND PROCEDURES
Section 6

2. Laying Out
Process of scribing or marking center points, circles, arcs, or straight lines on metal
Indicates shape of object
Amount of metal to be removed
Position of holes to be drilled
Layouts made from baseline
Layouts of two types: basic (semiprecision) and precision

3. Basic Layout Materials, Tools, and Accessories
Unit 19

4. Objectives Prepare a work surface for layout
Use and care for various types of surface plates
Identify and use the main basic layout tools and accessories

5. Layout Solutions Layout very important to accuracy of finished product
Surface of metal coated with layout solution to make layout lines visible
Surface should be clean and free of grease
Several types of solutions available

6. Types of Solutions Layout dye or bluing Copper sulfate solution
Most common
Quick-drying, good sharp background
Copper sulfate solution
Few drops of sulfuric acid added to solution gives copper-colored surface
Used on ferrous metal only
Surface must be absolutely clean of grease

7. Types of Solutions Mixture of vermilion powder and shellac Chalking
Used for Aluminum
Alcohol used to thin solution or remove it
Chalking
Mixture of lime and alcohol
Used for castings and hot-rolled steel
Readily clings to rough surface of castings

8. Layout Tables and Surface Plates
Work performed on layout table or surface plate (Granite or Cast-iron)
Granite considered better (Black, Pink, Gray)
Do not become burred
Do not rust
Are not affected by temperature change
Do not have internal stresses and therefore will not warp or distort
Are nonmagnetic
Can be used for checking near grinding machines
Are cheaper than similar-size cast-iron plate

9. Care of Surface Plates and Layout Tables
Keep working surface clean
Cover plate or table when it is not in use
Carefully place work on surface plate
Use parallels under workpiece whenever possible
Never hammer or punch any layout on surface plate
Remove burrs from cast-iron plates and protect surfaces with thin film of oil when not in use

10. Scribers
Has hardened steel point(s) and on some one end bent at angle for hard-to-reach places
Point must always be sharp
Honed frequently on fine oilstone
Knife-edge scribers used for extremely fine lines
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11. Dividers and Trammels
Dividers used for scribing arcs and circles on layout and transferring measurements
Spring divider most common type
Creates circles in sizes from 3 to 12 in
Trammel
Consists of beam on which two sliding or adjustable heads with scriber points are mounted
Can do larger circles
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12. Hermaphrodite Calipers
One curved leg and one straight leg with scriber point
Used for laying out lines parallel to an edge and locating center round or irregular- shaped stock
For parallel lines hold scriber at 90º to edge
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13. Squares
Used to lay out lines at right angles to machined edge, test accuracy of surfaces that must be square, and set up work for machining
Adjustable squares used for general work
Solid square: beam and blade
Used where greater accuracy required
Master squares
Used to check accuracy of other squares

14. The Combination Set Used extensively in layout work
Consists of steel rule, square head, bevel protractor and center head
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15. The Combination Set Steel rule fitted to other three parts
Square head Used to lay out angles at 45º and 90º and parallel to edge lines
Bevel protractor used to lay out and check various angles (0º to 180º)
Accuracy is ± 0.5º (30')
Center head forms center square when mounted on rule
Used for locating centers of ends of round , square, and octagonal stock

16. Used on surface plate to scribe parallel lines
Surface Gage
Consists of base, spindle, and scriber
Used on surface plate to scribe parallel lines
Some have a V-groove machined in the base, which allows them to be used on cylindrical work
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17. Layout or Prick Punches and Center Punches
Difference only in angle of point
Prick punch ground to angle of 30º to 60º
Used to permanently mark location of layout lines
Center punch ground to 90º
Used to mark location of centers of holes
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18. Layout Lines
After scribed on workpiece, should be permanently marked by means of layout or prick-punch marks
Ensures layout line location visible should line be rubbed off through handling
Intersection of circle centerlines prick-punches then enlarge with center punch
Automatic center punches produces uniform spacing of marks

19. Layout Accessories Angle plate and toolmaker's clamp Parallels
Used when lines are required on face of plate
Possible to scribe intersecting 90º lines accurately
Parallels
Used to raise workpiece and maintain work surface parallel to top of surface plate
V-blocks
Used to hold round work for layout and inspection
Keyseat rules and keyset clamps
Used to draw lines parallel to axis of shaft