Agricultural Mechanics 1 Kingsburg High School

1. Cold Metal Agricultural Mechanics 1 Kingsburg High School

2. Identifying Metals • All metals are either ferrous or nonferrous • Ferrous metals contain iron(Fe) • Nonferrous metals do not

3. Types of Ferrous Metals • Cast Iron- iron poured into a mold • Wrought Iron- almost pure Fe • Mild Steel- carbon is added to iron • Tool Steel- contains specific amounts of iron to be hardened

4. Cont. • Stainless Steel- adding nickel & chromium to steel • Plated Steel- coated steel w/ metals such as tin or zinc • Ex. Galvanized Steel

5. Nonferrous Metals • Aluminum- tough, light weight, and has a silver-like color • Copper- excellent conductor of electricity & makes up the bulk of the metal used in brass and bronze • Lead- very soft, heavy & malleable • Tin- used to coat steel for temp. rust prevention

6. Marking Metal • Scratch Awl • Scribe • Files • Soapstone/ Chalk • Dividers • Center Punch

7. Cutting Metal • Hacksaw • Files • Snips & Shears • Cold Chisels

8. Bending Metal • Mild steel can be bent in cold sizes up to ½” square or round & up to 3/16”x 1” flat • A vise anchored to a bench makes bending possible

9. Fastening Metal • Metals are fastened w/ various devices such as screws, bolts, and rivets • Metal can also be fastened together by melting a second metal between two pieces • Examples- soldering, brazing, & welding

10. Making Holes in Metals • Drilling holes are usually done w/ a portable drill or power drill press. • Only high-speed twist drills are recommended for drilling metal.

11. How To Drill In Metal • Use a center punch & make a small dent at the center. • Secure the metal w/ a clamp, vise, etc. • Apply firm, even pressure to the drill and keep the drill perpendicular to the metal. • Add cutting oil to carry away heat & debris. • Remove any metal w/ a file when done.

12. Threading Metal • Threads may be cut into a hole in metal w/ a tap. • A tap is a hardened, brittle tool that cuts threads into a hole. • A tap is turned w/ a tap wrench.

13. Threading Metal (cont.) • Threads are cut onto a rod or bolt w/ a die. • A die is turned w/ a die stock. • Common types of threads used are National Course(NC), National Fine(NF/SAE), & metric.

14. Fastening Metal Using Bolts & Screws • Flat pieces of metal are fastened quickly and easily w/ bolts. • Bolt & Nut • Bolt w/out Nut • Sheet Metal & Dry Wall Screws

15. Fastening w/ Rivets • A rivet is a device held in place by spreading one or both ends. • A special tool called a rivet set makes it easy to install rivets.

16. Types of Rivets • Steel Rivet- The round head of a steel rivet is used in structural and sheet steel bridges, buildings, and truck bodies. • Copper Rivet- Usually used on leather products. • Pop Rivet- It “pops” when it is installed. Very useful in hard to reach places.

17. Soldering • Solder is a mixture of tin & lead or other metals. • Is commonly used to join thin metal, copper tubing and pipe. • 50-50 solder is made of 50% tin and 50% lead.

18. Soldering (cont.) • Solder may be purchased w/ flux inside. This is called hollow core solder or flux core solder. • A soldering copper is a tool used for soldering and consisting of a wooden or plastic handle, steel shank, and copper tip. • Soldering copper wires for low-voltage applications can also be done.

19. Soldering (cont.) • The process of soldering a piece of copper pipe into a fitting is called sweating. • Sweating can be useful for repairing and installing water lines at home, on the job, or on the farm.

20. Summary • Metal can be fastened using a variety of means. The correct method depends on the thickness of the metal, the appearance needed, the strength needed and the cost. Choosing and applying the correct method is crucial to the success of any metal working project.