Modern Metalworking, 9th Edition Page 105 (105 of 672)

Chapter 6 Layout Work 105
2. Cut the stock to size. Remove all burrs (sharp
edges remaining on the metal after cutting,
stamping, or machining).
3. Clean the work surface. Remove any oil and
grease and apply layout dye to the metal.
4. Locate and scribe the layout reference lines or
base lines. Make all of your measurements
from these lines. If the material has one true
edge, it can be used in place of a reference line.
5. Locate the center points of all circles and
arcs.
6. Use a prick punch, Figure 6-30A, to mark the
points where the centerlines intersect. The
sharp point of this punch makes it easy to
locate these points. After a mark has been
checked and found on center with the prick
punch, it is enlarged with a center punch. See
Figure 6-30B.
7. Use a divider to scribe in all circles and arcs.
8. Scribe in any necessary angular lines. Use the
proper protractor measuring tool or locate
and connect the correct points by using a rule
or straightedge.
9. Scribe in any other internal openings and lines.
10. Complete the layout with clean, sharp lines.
Any double lines or sloppy line work should
be removed by cleaning the metal with a
solvent. Apply another coat of dye and then
scribe the lines again.
6.6 SAFETY PRECAUTIONS FOR
LAYOUT WORK
Proper safety must always be practiced
when performing layout work. Layout tools are
Figure 6-28.
This drawing provides the information necessary to make a simple layout.

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Chapter 6 Layout Work 105
2. Cut the stock to size. Remove all burrs (sharp
edges remaining on the metal after cutting,
stamping, or machining).
3. Clean the work surface. Remove any oil and
grease and apply layout dye to the metal.
4. Locate and scribe the layout reference lines or
base lines. Make all of your measurements
from these lines. If the material has one true
edge, it can be used in place of a reference line.
5. Locate the center points of all circles and
arcs.
6. Use a prick punch, Figure 6-30A, to mark the
points where the centerlines intersect. The
sharp point of this punch makes it easy to
locate these points. After a mark has been
checked and found on center with the prick
punch, it is enlarged with a center punch. See
Figure 6-30B.
7. Use a divider to scribe in all circles and arcs.
8. Scribe in any necessary angular lines. Use the
proper protractor measuring tool or locate
and connect the correct points by using a rule
or straightedge.
9. Scribe in any other internal openings and lines.
10. Complete the layout with clean, sharp lines.
Any double lines or sloppy line work should
be removed by cleaning the metal with a
solvent. Apply another coat of dye and then
scribe the lines again.
6.6 SAFETY PRECAUTIONS FOR
LAYOUT WORK
Proper safety must always be practiced
when performing layout work. Layout tools are
Figure 6-28.
This drawing provides the information necessary to make a simple layout.

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104 Modern Metalworking
plate can be placed in almost any position to
establish a perpendicular edge. The work is
commonly clamped to the face of the plate for
layout, measurement, or inspection tasks.
6.4.4 Box Parallels
Accurate surfaces parallel to the surface
plate can be obtained by using box parallels,
Figure 6-25. These tools are available in a number
of sizes. Each tool surface is precisely ground to
close tolerances for accuracy.
6.4.5 V-Blocks
V-blocks are used to support round work for
layout and inspection. See Figure 6-26. These
tools are furnished in matching pairs with
surfaces ground square to close tolerances. Ribs
are cast into the body of the block for strength
and weight reduction; they are also used as
clamping surfaces. V-blocks are available in a
number of sizes.
6.4.6 Straightedge
Flat surfaces can be checked with a straight-
edge, Figure 6-27. The tool can also be used to lay
out long, straight lines. Straightedges are
manufactured from steel or granite in a wide
range of sizes. They must be carefully handled to
prevent nicks to the reference edge.
6.5 MAKING A LAYOUT
Each layout job has its own specifications
and number of operations. Before any layout
operation can be started, the tasks and tools
required to complete the job should be carefully
considered. Once a drawing is studied closely
and the necessary operations are determined, the
metal should be prepared and marked properly.
A drawing for a typical job is shown in
Figure 6-28. The following steps are used to
complete the layout:
1. Study the drawing carefully and then plan
the layout sequence, Figure 6-29.
Figure 6-26.
V-blocks are available in a number of sizes. They
support round work for layout and inspection.
Figure 6-24.
Right angle plates are used as square references in
layout and inspection.
Figure 6-25.
Box parallels.
Figure 6-27.
Straightedges are employed to lay out long, straight
lines. They are commonly made from steel or granite.

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sharp objects and require careful handling. Large
pieces of metal stock and other materials can
pose hazards and must be handled safely.
The following precautions should be
observed when laying out a job:
Never carry an open scriber, divider,
trammel, or hermaphrodite caliper in your
pocket.
Always cover all sharp tool points with a cork
when the tool is not in use. When laying out
work, place tools on the bench with the
points facing away from you.
Avoid handing a sharp tool to another
person with the pointed end sticking out.
Wear goggles when grinding the points of a
scriber.
Get help if you have to move heavy angle
plates, large V-blocks, or other large
equipment.
Remove all burrs and sharp edges from the
stock before starting the layout.
106 Modern Metalworking
1. Cut the stock to the
approximate size.
2. Locate and scribe
the base lines.
3. Locate and scribe the
circle and arc centerlines.
4. Scribe in the circles
and arcs.
5. Locate and scribe the
angular lines.
6. Scribe in the remaining
lines.
Figure 6-29.
The sequence of steps involved in laying out the job shown in Figure 6-28.

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