METALLIC ORE-mined beneath the earth surface.

IRON-produced from iron ore while copper is produced from copper ore.
ALUMINUM-produced from an ore called bauxite.
BLAST IRON -used to produce metal by passing hot gases to the furnace that is mixed with iron ore, limestone, and coke at about
3000 C.
PIGS-melted and poured into mold to make iron, steel, and cast iron

Metal Characteristics:

1. Hard
2. Easy to shape
3. High melting temperature
4. Low specific heat
5. Good electrical conductivity
6. Good thermal conductivities
7. Ability to be deformed without fracture

Classifications of Metal

PURE METAL- - are single element that are not combined with any other chemical element. They are too soft, low and strong, or
low in some other desired property to be used in commercial applications.
ALLOYS- are mixture of two or more metal to produce new metal. Example are stainless steel, bronze, etc.
PIG IRON - is produced from ore of hematite or magnetite in the blast furnace by melting with limestone and coke.
CAST IRON- with carbon content of 1.7 to 6/7%. They are low cost, good casting property, high compressive strength, high
wearing resistance, brittle and lower tensile strength
STEEL-It is a molten steel that is cast into an ingot and then rolled, forged, hammered, pressed, or machine into desired shape
Soft Centered Steel - is durable to shock because the mild steel in the center layer is deformable and has higher wear resistance than
hard steel at the outer side. They are usually used for moldboard and share of a plow.
Low Carbon Steel- with carbon content not exceeding 0.25%.
Medium Carbon Steel- contains 0.25 to 0.50% carbon. They are usually used in making structural and machinery steel.
High Carbon Steel - carbon content is above 0.50%. They are usually used in the manufacture of spring and tool steel.
Mild Steel (MS) - contains carbon of 0.15 to 0.25%. They are malleable and easy to cut and weld.
Cold Rolled Steel (CRS) - are medium carbon steel which are used for parts and components of machine requiring greater strength
and hardness such as shafting and connecting rods.
Stainless Steel (SS) - They have high resistance to corrosion and oxidation. They are used for valves, nozzles, and dairy machines.
Non- Ferrous- Includes all the metals such as copper, aluminum, magnesium, and zinc in which iron is not present in large amount.
Sheet- a piece of metal which has been rolled into a sheet of 3/16 in. or less in thickness.
STRIPS- a long sheet of metal that is less than 12 in. wide
PLATE- a metal with thickness over 3/16 in. Commonly available size is 4' wide x 8' long. Thickness are given in terms of mm or
in inch.
METAL BARS- made of different shapes and are usually available in standard length of 20 ft or 6 meters. They are purchased in
terms of quantity, shape, size, and kind of metal used.
STRUCTURAL SHAPES- commonly used in the construction of agricultural machines. They are specified in terms of quantity
wanted, the kind of material and shape, size, and length of each piece.
Tubular Products- includes all hollow metal shapes such as pipes and tubes. They are available in round, square, and rectangular in
shape. Specifications are given in terms of shape, schedule number, size, and length.
Non-Metallic Materials

1. Wood
2. Plastics
3. Rubber
4. Ceramics
5. Fibers
6. Glass
SHEARING- This is done by placing a piece of metal usually in the form of sheet, plate, strip, or rod between two blades of knives.
Metal shears-The machine used for metal shearing
Bench shears- are used for cutting heavy sheet metal and metal plates
Tin shear or snip- is used for cutting metal sheets using hand
Sawing- It is the process of moving a hard metal saw blade with teeth along its edge across a metal to be cut.
Hand Hacksaw- It is the process of moving a hard metal saw blade with teeth along its edge across a metal to be cut.
Power Hacksaw- It is the process of moving a hard metal saw blade with teeth along its edge across a metal to be cut.
Bandsaw- It uses an endless blade which move past the piece being cut in only one direction
FLAME CUTTING-It is one of the fastest method of cutting bars or steel plates having a thickness of 1/16 to 6 inches.
-It is one of the fastest method of cutting bars or steel plates having a thickness of 1/16 to 6 inches.
Milling Processes
Facing- It is the process of cutting or squaring of the end of a piece of work.
Center Drilling- It is done with a combination drill and countersink
Straight Turning- The work is first placed on the centers, and the cutting tool is set for cutting.
Drilling Reaming, and Counter Boring- These are commonly performed with a drill press or by a lathe.

Knurling- It is the process of making the handle of hand tool rough in order to give a better grip.
Boring-It is the cutting and enlarging of a round hole to make a more exact size and accurate with its axis.
Threading- It is the process of making a threads on screw either right-hand, left-hand, external, or internal threads.
Welding Processes:
1. Soldering
2. Brazing
3. Oxyacetylene Welding
4. Arc Welding
5. Resistance Welding
6. MIG Welding
7. TIG Welding

Soldering- It is the common method of joining metal sheet especially non- ferrous metal.
Brazing-It is the joining technique of metal using oxyacetylene welding equipment by melting a non-ferrous filler rod at a
temperature above 427 C but below the melting point of metal being joined.
Oxyacetylene Welding-It is the joining technique of metal using oxyacetylene welding equipment by melting a non-ferrous filler
rod at a temperature above 427 C but below the melting point of metal being joined.
Regulator- It the special valve to properly mix the oxygen and the acetylene gas.

Hose- It the special valve to properly mix the oxygen and the acetylene gas.
Resistance Welding-It uses the heat generated by electric current passing through a small area of the metal being joined. The
pressure forces heated the area together until they have fused.
Spot welding- is the common form of resistance welding.
Arc Welding- It is the process of welding metal by passing high current into a flux-coated welding rod. The flux serves as shield to
prevent oxidation to produce stronger weld.
MIG Welding- It uses continuous roll-fed welding rod.
Inert gas- is used to protect the weld from oxidation. For steel it sues carbon dioxide while for aluminum and other metals, a
mixture of argon and helium is used.
TIG Welding-The tungsten inert gas welding is widely used for welding aluminum, stainless steel and other non-ferrous metals.
- It is similar to oxyacetylene welding in that the filler rod is separate from the torch and is fed with the opposite hand.
PROPERTIES OF MATERIALS
Physical Property:
Density-mass per unit volume
Anisotropy- characteristic of exhibiting different values of a property in different directions
Machinability-relative ease of machining or the satisfaction with which a material is cut by sharp tools in various operations
Mechanical Properties:
Static strength- standard tensile test in obtaining various characteristics and strengths of materials
Stress- standard tensile test in obtaining various characteristics and strengths of materials
Tensile stress-stress that tends to stretch or lengthen the material (normal stress)
Compressive stress-stress that tends to compress or shorten the material (normal stress)
Shearing stress-stress that tends to shear the material (shear stress)
Strain- deformation of a solid due to stress
Normal strain- elongation or contraction of a line segment
Shear strain- change in angle between two line segments originally perpendicular
Shear modulus- - ratio of shear stress to the shear strain. Also called as Modulus of Rigidity
Bulk modulus of elasticity (K) - a measure of a resistance of a material to change in volume without change in shape or form
Poisson's Ratio- a measure of a resistance of a material to change in volume without change in shape or form
Proportional Limit- stress-strain curve is a straight line
Young's Modulus/ Modulus of Elasticity - the slope of the stress-strain diagram from O to P
Elastic Limit- limit beyond which the material will no longer go back to its original shape when the load is removed
Yield Point- point at which the material will have an appreciable elongation or yielding without any increase in load
Ultimate Strength- maximum ordinate in the stress- strain diagram
Rupture Strength- strength of the material at rupture
Engineering stress-stress by considering the original cross-sectional area of the body
True stress-stress determined by the instantaneous load acting on the instantaneous cross-sectional area
True strain- rate of instantaneous increase in the instantaneous length

Torsional strength- found by twisting bars and recording the torque and the twist angle
Working stress- the actual stress of a material under a given loading
Allowable stress- maximum safe stress that a material can carry. It is taken as either the yield point or ultimate strength divided by a
factor of safety
Factor of safety- maximum safe stress that a material can carry. It is taken as either the yield point or ultimate strength divided by a
factor of safety
Ductility- measure of a material's ability to undergo significant plastic deformation before rupture or percent area reduction from a
tensile test
Brittleness- material will fracture without appreciable prior plastic deformation. Lack of ductility glass, concrete, ceramics, stone,
gray cast iron
Malleability- material can be plastic deformed and shaped when cold
Hardness- measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion
Brinell Hardness Test- applying a known load to the surface of the tested material through a hardened steel ball of known diameter
Creep- the time dependent deformation due to heavy load over time
Fatigue- when a material is subjected to repeated cycles of stress or strain and its structure breaks down and ultimately leads to
fracture
Thermal Properties
Melting point- temperature at which a material turns to liquid from solid.
Latent heat of fusion- temperature at which a material turns to liquid from solid.
Specific heat- the amount of heat required to raise the temperature of 1kg of material by 1°C
Thermal conductivity- measure of heat flow through a material
Thermal diffusivity- the thermal conductivity of a substance divided by the product of its density and its specific heat capacity.
Thermal expansion coefficient- change in dimensions that occur as the temperature increases or decreases
Environmental Properties
Dry corrosion-chemical reaction of solid surface with dry gasses usually a metal reacting with oxygen and forms a layer of oxide
Flammability- ability of materials to suppress combustion
Wet corrosion- caused by reaction of metal with water, brine acids, or alkalis