Transcript METAL FASTENING UNIT - Central Columbia School District

METAL FASTENING UNIT
IDENTIFYING METALS
2 CLASSIFICATIONS OF METALS
Ferrous-obtained from iron ore
Non-ferrous-does not contain iron
Alloy- combination of 2 or more metals
- contains characteristics that make it
different form original metals
- made to improve the strength & quality of
the metal
- carbon is added to iron to make steel
FERROUS METALS
Mostly iron
-iron-refined iron ore
identified by magnetic and gives off sparks
when applied to a grinding wheel
-usefulness increased with the addition of
carbon to create steel
-combined with other metals, becomes very
corrosion-resistant material called
STAINLESS STEEL
CAST IRON:
Malleable=workable
pour molten iron into a mold called a CASTING
CHANNELLOCK VIDEO-TOOLS
Ductile-metal can be bent slightly without
breaking
malleable cast iron
Wrought Iron- pure iron-very malleable-resists
rust-railing
Mild Steel- workhorse of metals
-tough
-ductile
-strong
-malleable
SHAPES OF STEEL
FLAT BANDS
ANGLES
CHANNELS
TEES
I-BEAMS
RODS
PIPE
TOOL STEEL
Contains specific amount of carbon
-permits it to be hardened
Annealed-heat a metal to proper treatment & then
slowly cool the metal
Hardened- heating to proper temperature & than
rapidly cooling the steel in water
*degree of hardness is determined by controlling
the temperature of the metal & the speed of
cooling
Tempering- controlled reheating & cooling of
steel after it has been shaped
Results: degree of hardness-relieves stressprevents cracking
STAINLESS STEEL
Created by adding nickel & chromium to steel
Plated Steel
Steel is made rustproof by applying a coating of
metal such as tin or zinc
Zinc Coated- galvanized steel
rust resistance depends upon thickness of
the zinc coating-rated in ounces of zinc
NON-FERROUS METALS
Does not contain iron
Examples: zinc-copper-aluminum-lead-tin
ALUMINUM:
-tough
-silver color
-lightweight
-electrical conductor
Corrosion- reaction of metals to liquids & gases
that cause them to deteriorate or
break down
Copper
Electrical conductor
corrosion is slight
Brass-60% to 90% copper & the remainder is
zinc
Bronze-copper, zinc and 10% tin
LEAD
solder-soft alloy used in making joints for metals
TIN
Temporary rust protectant
MARKING METAL
Steel-most commonly used metal
TOOLS
Scratch Awl
Soapstone
Scriber
Dividers
File
Center Punch
CUTTING METAL
Hacksaw
Cold Chisel
File
Snips
Shears
Using a hacksaw, select a blade fine enough to
allow at least 3 teeth at a time on the metal
surface
Standard Blades: lengths-10” or 12”
teeth per inch-14, 18 or 24
32 teeth per inch very small
Thicker the metal, coarser the teeth
Designed to cut on the forward stroke
install blades with the teeth pointing away
from the handle
FILES
Classified by-length, shape, design of teeth and
coarseness of teeth
8” to 12” in length
Shapes:
triangular
round
flat
half-round
Single-Cut Files-straight teeth going in one
direction
Double-Cut Files-teeth going in 2 directions
Both can be purchased in: coarse, second-cut
medium and smooth fine grades
Files cut on the forward stroke only
Draw-filing:
Placing the file at a 90 degree angle to the metal
and pushing or pulling the file in this position
Stock-refers to a piece of material
SNIPS/SHEARS:
Large scissor-like tools for cutting sheet metal
Cold Chisel-piece of tool steel shaped, tempered
and sharpened to cut mild steel
Eye- piece of metal bent into small circles
Anvil- heavy steel object that is used to aid in
cutting and shaping metal