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OBJECTIVE: AM24.02 Identify, cut, drill, bend, shape, file, and grind cold metals. Metals. Identifying Metals. Ferrous contain iron– must be painted Nonferrous has no iron Metals Color Weight Texture Use Shape Spark test. Identifying Metals . Spark Test Cast iron- red lines
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OBJECTIVE: AM24.02 Identify, cut, drill, bend, shape, file, and grind cold metals. Metals
Identifying Metals • Ferrous contain iron– must be painted • Nonferrous has no iron • Metals • Color • Weight • Texture • Use • Shape • Spark test
Identifying Metals • Spark Test • Cast iron- red lines • High carbon steel- yellow lines/star bursts • Wrought 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
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.