1. Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Unit 12 Identifying, Marking, Cutting, and Bending Metal

2. Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Metals Ferrous or nonferrous Most metals are not used in their pure form Alloys made to improve certain qualities of the pure metal

3. Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Ferrous Metals Mostly iron Rust easily Magnetic Most useful for making tools and machinery

4. Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Types of Ferrous Metals Cast iron: grainy, not easily shaped or bent Wrought iron: almost pure iron, very malleable, resists rust Mild steel: the workhorse of metals; tough, ductile, and malleable

5. Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Types of Ferrous Metals (continued) Tool steel: contains carbon; can be hardened Stainless steel: very tough, will not rust, resists corrosion Plated steel: rustproof; coated in tin or zinc

6. Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Nonferrous Metals Do not contain iron More expensive than ferrous metals Limited supply

7. Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Types of Nonferrous Metals Aluminum: silver-white in color; tough, lightweight, resists corrosion Copper: excellent electrical conductor; corrosion resistant in air or water Lead: very soft and heavy Tin: used to coat steel for temporary rust protection

8. Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Marking Metal Metals are either shiny or very dark in color; therefore, special tools are needed for marking metal Tools –scratch awl –scriber –file –soapstone –dividers –center punch

9. Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Cutting Metal Can be accomplished by sawing, shearing, filing, or grinding Tools –hacksaw: blade selected should allow at least three teeth to contact the metal at one time –file: classified by length, shape, design, teeth, and coarseness of teeth –snips: scissor-like tool used to cut metal –cold chisel: used to cut mild steel when driven with a hammer

10. Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Bending Metal Use a vise anchored to a heavy bench to bend cold metal Can bend mild steel up to ½'' square, ½'' round, or 3/16''  1'' flat Eye: piece of metal bent into a small circle

11. Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Important Terms Alloy: combination of two or more metal elements Malleable: workable Casting: a mold Ductile: can be bent slightly without breaking Malleable cast iron: combination cast iron core and ductile outer layer Anneal: to heat and then slowly cool a metal to soften and toughen the steel

12. Copyright © 2010 Delmar, Cengage Learning. ALL RIGHTS RESERVED. Important Terms (continued) Tempering: carefully controlled reheating and cooling of steel after it has been shaped Galvanized steel: zinc-coated steel Corrosion: reaction of metals with liquids and gases that cause them to break down Solder: soft alloy used to join many kinds of metal Drawfiling: placing the file at 90 degrees to the metal and pushing or pulling the file in this position Stock: a piece of material