Metals

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.