Working with Sheet Metal
Straight edges can be cut onto sheet metal stock using a shear. Ensure
that the shear is rated to cut the gauge of sheet metal you're working
with, or you may damage the blade. The gauge rating of a shear is
generally marked prominantly on the machine. Sheet stock should be
placed on the table and slid below the plexiglass shield. When the
stock is oriented properly, make a cut by stepping down on the treadle.
When the material shears, the treadle may slam down forcefully. The
treadle stops are designed to prevent the treadle from crushing your
someone's foot. Still, it is good practice to make sure your other foot
isn't benieth the treadle.
The machine shown above will create 90 degree notches in sheet metal.
This makes it possible to create profiles that can then be bent into
three dimensional shapes (like boxes). Lay the work on the table. The
guides can be used to help orient the part as desired. Pulling on the
actuating lever will cut a notch in the work.
A Press Brake
A press brake can be used to bend sheet metal. The work must be slid
under the shoes. Raise the shoes with the elevation levers, slide the
work in place, and lower the shoes back down. The radius of the bend
can be set with adjustment bolts on both sides of the machine. Minimum
bend radius is a function of the ductility and thickness of the material
being worked. For aluminum sheet, the bend radius should be greater
than the sheet thickness. Bend the work by applying force to the bending
lever. It is necessary to bend the work slightly beyond the desired
angle as the metal will "spring-back"; elastic deformation is recovered
when the bending force is relaxed.
Return to the machine shop.
Return to the Mechanical Engineering Department.