layout and the measurements are correct. After
determining that the layout is accurate, the layout person
should center punch all cutting lines. This ensures
accurate cutting with either a torch or shears. The work
can be checked after cutting because each piece will have
one half of the center punch marks on the edge of the
material. Remember, always cut with the kerf of the
torch on the outside edge of the cutting lines.
LAYOUT OF STRUCTURAL SHAPES
Structural shapes are slightly more difficult to lay
out than plate. This is because the layout lines may not
be in view of the layout person at all times. Also, the
reference line may not always be in view.
Steel beams are usually fabricated to fit up to
another beam. Coping and slotting are required to
accomplish this. Figure 3-32 shows two W 10 x 39
beams being fitted up. Beam A is intersecting beam B
at the center. Coping is required so beam A will butt
up to the web of beam B; the connecting angles can be
welded to the web, and the flanges can be welded
A cut 1 1/8 inches (2.8 cm) long at 45 degrees at
the end of the flange cope will allow the web to fit up
under the flange of beam B and also allow for the fillet.
The size of the cope is determined by dividing the
flange width of the receiving beam in half and then
subtracting one half of the thickness of the web plus
1/16 inch. This determines how far back on beam A
the cope should be cut.
When two beams of different sizes are connected,
the layout on the intersecting beam is determined by
whether it is larger or smaller than the intersected
beam. In the case shown in figure 3-33, the
Figure 3-33.Typical framed construction, top flange flush.
Figure 3-32.Fabrication and fit-up for joining two beams of the same size.