METALSOBJECTIVE: AM24.02
Identify, cut, drill, bend, shape, file, and grind cold metals.
Identifying Metals Ferrous contain iron– must be painted Nonferrous has no iron Metals
ColorWeightTextureUseShapeSpark test
Identifying Metals Spark Test
Cast iron- red linesHigh carbon steel- yellow lines/star burstsWrought iron- straw colored lines w/o bursts
Galvanized steel should not be cut or welded
Drilling Center punch Drill- use oil Use round file to smooth hole
OBJECTIVE: AM25.01 Examine oxy-fuel procedures.
Oxy-Fuel Procedures Used to cut through metal, heat for
bending, or for welding Fuels include propane, propylene, or
acetylene Acetylene is most often used Oxygen enhances the flame-will not
burn
Oxy-Fuel Use soapy water to check for leaks in
hoses Acetylene pressure should be less than
15psi Open the acetylene valve ¼ to ½ turn Only use spark lighter
Types of Flames When first lit, you have a carbonizing
flame Oxygen is adding to make a neutral
flame Extra oxygen makes an oxidizing flame
for special applications where extra heat is needed
Arc Welding AC- inexpensive welder used most of
the time DC- generator operated, used where
power is not available Some welders are both AC and DC
Welding TIG- Tungsten Inert Gas Good for welding stainless steel &
aluminum Gas supply is helium & argon
MIG Welding Metallic Inert Gas Wire feed welder Can be used as automatic welder
Welding Equipment Helmet leather gloves leather aprons leather welding jacket leather boots
Welding Equipment Chipping hammer Clamps Vise grip clamps
Electrodes Rods covered in flux Have a classification system
Example: E6011
Electrodes 6011 is good for all purpose work 6013 is also good but only has medium
penetration
Welding Procedures Metal should be cleaned before welding ¼” or thicker metal should be beveled &
place 1/16 to 1/8” apart
Setting the Amperage Amperage too low causes a narrow,
high bead with poor penetration. Amperage too high caused a flat bead
with excessive spatter. Correct amperage helps make a uniform
bead with bead width and penetration depth equal to each other.
Welding in the flat position When the electrode sticks, wiggle it back
and forth Tapping or scratching methods can be
used to strike an arc Arc length should be the same as the
diameter of electrode.