NAME: Evangelista, John Kennedy P.
SECTION: BSABEn 3
DEADLINE: November 7, 2023
COURSE WORK: #4 Engineering Materials
Engineering Materials
Engineering Materials as defined by the Philippine Agricultural Engineering Standard (PAES).
These materials are necessary for many types of agricultural machines and buildings.
V-Belts and Pulleys:
Usage: V-belts transmit power between shafts and are commonly used in agricultural machines for
driving components like fans, pumps, and conveyors.
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Designations: Look for belts with designations such as A, B, C, etc., which correspond to different
sizes and load capacities.
Design Considerations: Consider factors like load, speed, temperature, and alignment when
selecting V-belts and pulleys.
Flat Belts and Pulleys:
Usage: Flat belts also transmit power but have a flat profile. They’re suitable for applications where
space is limited.
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Designations: Flat belts may have designations based on their width and material composition.
Design Considerations: Ensure proper tension, alignment, and material compatibility for optimal
performance.
Roller Chains and Sprockets:
Usage: Roller chains are common in agricultural machinery for transmitting rotary motion.
Sprockets engage with the chain.
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Designations: Roller chains come in various sizes (e.g., 40, 50, 60) based on pitch.
Design Considerations: Lubrication, alignment, and load capacity are critical factors.
Keys and Keyways:
Usage: Keys and keyways connect rotating components (e.g., shafts and gears) to prevent slippage.
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Designations: Keys may be designated by their dimensions (e.g., 6 mm × 6 mm).
Design Considerations: Material strength, fit, and keyway dimensions matter.
Shafts:
Usage: Shafts transmit torque and rotational motion. They’re essential components in various
agricultural machines. The term shaft usually refers to a component of a circular cross-section that
rotates and transmits power from a driving device, such as a motor or engine, through a machine.
Shafts can carry gears, pulleys, and sprockets to transmit rotary motion and power via mating gears,
belts, and chains.
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Designations: Shafts may be labeled based on diameter, length, and material.
Design Considerations: Material selection, stress analysis, and alignment are crucial.
Spur Gears:
Usage: Spur gears transfer motion between parallel shafts. They’re common in gearboxes.
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Designations: Spur gears are designated by pitch, number of teeth, and material.
Design Considerations: Tooth profile, load distribution, and backlash are important.
Helical Gears:
Usage: Helical gears also transmit motion between parallel shafts but with improved load
distribution and reduced noise.
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Designations: Similar to spur gears, helical gears have pitch and tooth count designations.
Design Considerations: Helix angle, tooth contact, and lubrication matter.
Anti-Friction Bearings:
Usage: Bearings reduce friction between moving parts. Common types include ball bearings and
roller bearings.
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Designations: Bearings are labeled based on size, load capacity, and type (e.g., 6204).
Design Considerations: Load, speed, and environmental conditions influence bearing selection.
Journal Bearings:
Usage: Journal bearings support rotating shafts. They rely on a fluid film for lubrication.
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Designations: Typically identified by dimensions (e.g., 40 mm × 60 mm).
Design Considerations: Lubrication, clearance, and material compatibility are critical.
Bolts and Nuts:
Usage: Bolts and nuts secure components together. They’re essential for assembling machinery.
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Designations: Bolts and nuts have standardized markings (e.g., M12 × 1.5).
Design Considerations: Strength, thread type, and corrosion resistance matter.
Rivet
UsageRivets are used primarily for moderately loaded joints. Unlike screws, rivets are not precision
items; its main advantage is its high speed of assembly. For the purpose of this standard, machine
member riveted joints will be discussed.
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Designations: Rivets shall be designated by its type, nominal diameter, and its nominal length.
Design Considerations:Two of the most crucial design factors when using solid rivets are the
diameter and length of the rivets or tenons being formed.
Screws
Usage:Screws are used for fastening materials permanently or semi-permanently. When mentioned
in contrast to bolts, screws are used without assembling with nuts.Photos:
Designations:Bolts shall be identified as ISO Metric by either of the symbols “ISO M” or “M “.
Screws shall be designated by the following data in the sequence shown: product name, nominal
diameter; and thread pitch, nominal length, steel property class or material specification, and
protective coating, if required. EXAMPLE M8x1.25x30, Slotted Pan Head Machine Screw, Grade
4.8 Steel, Zinc plated
Design Considerations: The key specifications for a screw are its major diameter, thread pitch (or
its reciprocal thread count per unit length), and length. The major diameter is the diameter measured
at the outside of the screw threads.
Washer
Usage:Washer applications include: increasing the bearing area, keeping fasteners tight, surface
protection, spanning an oversize clearance hole, sealing, electrical connection, and spring tension
take-up devices.
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Designations: Washers shall be designated by the following data in the sequence shown: washer
classification, type or its symbol, nominal size, material or its symbol (Symbols for materials shall
be S for steel, SUS for stainless steel), and protective coating, if required. EXAMPLE Conical
spring, 1L, 8, S
Design Considerations:Washer sizes correspond to the screw/bolt diameter they fit. Washer
surfaces shall be smooth, free from flaws and cracks, rough surface, rust, and free from sharp edges
on outside periphery.
Pins
Usage: Pins offer an inexpensive and effective approach to assembly where loading is primarily in
shea
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Designations: Pins shall be designated by the following data in the sequence shown: pin
classification, type or its symbol, nominal size, nominal length, material. Example: Parallel pin, A,
6x30, Steel
Design Considerations: The surface of the pin shall be smooth and free from cracks, flaws, burrs,
rust, and gaps in contacting surface.
Metal Bars
Usage: Metal bars, pipes and tubes are used for components, structural framing and mechanical
elements for agricultural machinery and structures.
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Designations:
Bars shall be designated by the following data in the sequence shown: Bar classification,
dimensions, and material.
Pipes shall be designated by the following data in the sequence shown: Nominal size, classification,
length, and material.
Tubes shall be designated by the following data in the sequence shown: classification, dimensions,
and material.
Design Considerations:
Bars shall be clearly marked with the following items by an appropriate method on each bar
or on each bundle of bars.
1) Designation
2) Manufacturer’s name or its abbreviation
Deformed bars
The manufacturer’s identifying mark, bar size and grade shall be clearly embossed in
each bar.
a) The manufacturer’s identifying mark – a logo or symbol registered or to be registered with the
Philippine Patent Office and published in the Official Gazette.
b) Bar size – Arabic number reflecting the nominal diameter.
c) Grade – Dash (parallel to the rib) or the grade number itself
Pipes shall be clearly marked with the following items by an appropriate method on each pipe or on
each bundle of pipes.
Tubes shall be clearly marked with the following items by an appropriate method on each tube or on
each bundle of tubes.
Metal sheets and Plates
Usage: Sheets and plates are used for structural components in agricultural machinery and
structures.
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Designations:
Aluminium and Aluminium Alloy Sheet:The aluminium and aluminium alloy designation shall be
in accordance with AS 2848.1.
The temper designation shall be in accordance with AS 2848.1 and shall be used for all its forms of
wrought aluminium and aluminium alloys. It shall follow the alloy designation, the two being
separated by a dash.
Hot-Rolled Steel Sheet:The designation for analysis of grades shall consist of a five-character
alphanumeric system
in accordance of the following:
(a) First character, a letter indicating deoxidation practice, as follows:
A: Aluminium killed
K: Silicon killed, with or without aluminium addition
R: Rimmed
U: Unspecified deoxidation
NOTE: The character “U” indicates that the steelmaker has the option to decide on the deoxidation
practice.
(b) A four-digit series designation as follows, wherein the first two digits of the number
indicate the type of steel (10 for plain carbon steel and 15 for carbon-manganese steel) and
the last two digits indicate the approximate mean of the specified carbon range
Example of designation: A1006, XK1016, K10B55
Design Considerations:
Aluminium and Aluminium Alloy Sheet:
Rolled rectangular sections with a thickness over 0.15 mm up to 6.0 mm.
Edges can be sheared, slit, or sawn.
Galvanized Steel Sheet:
Galvanized flat or corrugated metal product cut to standard or specified length.
Nominal base metal thickness ranges from 0.20 mm to 1.6 mm.
Flat width: 760 mm to 1,220 mm.
Available as coiled (with slit edges) or flat (flattened or leveled, with sheared, slit, or sawn edges).
Hot-Rolled Steel Sheet:
Supplied in cut lengths, produced by cutting from a coil rolled on a continuous mill.
Width: at least 600 mm.
Nominal thickness: less than 3 mm.
Clutches, Couplings, and Splines
Usage: Couplings are used to join lengths of shafting, which must often be sectionalized for
practicability and economy in manufacture and shipping or for purposes of ready installation.
Clutches are couplings which permits the disengagement of the coupled shafts during rotation.
Splines are used for the transmission of power from a shaft to hub or vice versa.
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Designations:
Couplings size designation determines whether it is a 3, 4, 5 or 6-bolt design.
For example a size 153 coupling is a 3-bolt design.
Clutches Manual Transmission, Automatic Transmission, Automated Manual Transmission, and
Continuously Variable Transmission) and by Clutch Disc size (Below 9 inches, 9 inches to 10 inches
10 inches to 11 inches, and 11 inches and above)
Splines A spline assembly of nominal size 120 x 114, with 38 spline teeth and the fit 8 HE/8eb on
the effective and actual spline teeth shall be designated as: Spline Assembly 120 x 114 x 38 x 8
HE/8eb IS : 3665
Design Considerations:
Coupling- In order to assure adequate coupling life on pulsating loads, it is necessary to increase the
size of the coupling over that determined on a basis of maximum shaft size or rated power capacity.
The service factors given in Table 13 are representative values given in most catalogs and are to be
used in Equation 1, which allows for fatigue and overheating at higher speeds.
Clutch- should positively take the drive gradually without the occurrence of sudden jerks.
Splines- are grooves or teeth on a shaft that match up with grooves or teeth on another component to
transmit torque
Engineering Plastics
Usage: Engineering plastics are used as materials for manufacture of different machine and
structural components especially where corrosion resistance is a factor.
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Designations:
Plastic: A synthetic organic material capable of being shaped by casting or molding under increased
temperatures and pressures.
Monomer: The simple, unpolymerized form of a chemical compound.
Polymer: A chemical compound with higher molecular weight, consisting of structural units linked
together by covalent bonds.
Copolymer: Polymers consisting of more than one monomer.
Covalent Bond: A non-ionic chemical bond formed by shared electrons.
Thermoplastic: Substances that melt on heating and can be processed in this state through extrusion
and molding.
Thermosets: Substances that cannot be melted and remelted.
Design Considerations:
Acetal provides high strength and stiffness while offering enhanced dimensional stability and
ease of machining. This material is resistant to a wide range of chemicals, including many solvents.
And it is available in a broad range of grades), with properties addressing specific needs.
Cast acrylic shall be made from virgin acrylic monomer and offers superior optical clarity
and light transmission. It shall not affected by sunlight; it resists aging; and it remains stable
across a wide range of temperature, moisture, and exposure conditions. It will not crack,
craze, or corrode. It weighs half as much as comparable glass and yet has good shatter resistance
and durability.
Polyamide, also known as nylon is one of the most versatile and widely used thermoplastic
materials. Its physical properties and reasonable price combine to make it a popular choice
for numerous applications. It can replace steel, brass, bronze, aluminum, wood, and rubber,
while reducing noise, using less lubrication, and increasing gear life.
Polycarbonate is an amorphous thermoplastic with excellent dimensional stability and good
strength and stiffness over a wide range of service temperatures. It is often used for structural
applications when transparency and impact strength are essential-such as lenses, manifolds,
site glasses, and machine guards. Polycarbonate suits a wide variety of electrical applications
as well, because of its low moisture absorption, good insulation and excellent flammability rating.
For the purpose of this standard, only Ultra High Molecular Weight (UHMW) from the
different types of polyethylene shall be discussed. UHMWPE is 1/8 the weight of mild steel
but is high in tensile strength and as simple to machine as wood. Also unlike steel, it reduces
noise in many applications. It causes no undesirable taste, smell, or discoloration, and it can be
cleaned with water, steam,
detergents, or disinfectants. UHMW Polyethylene will withstand intermittent temperatures of
up to 100 °C (212 °F), while at the same time being ideal for use in freezing lines.
Polypropylene is noted for its light weight, being less dense than water; it is a polymer of
propylene. It resists moisture, oils, and solvents. Since its melting point is 121°C (250°F), it
is used in the manufacture of objects that are sterilized in the course of their use.
Polytetrafluoroethylene more popularly known as Teflon is based on chain of carbon atoms,
the same as all polymers. Given their good dynamic mechanical properties and sufficient
flexibility, PTFE and modified PTFE-based materials are ideally suited for use as dynamic
seals and bearings, even when the stress is extreme.
Polyvinyl chloride (PVC) is a thermoplastic that is a polymer of vinyl chloride. Resins of
polyvinyl chloride are hard, but with the addition of plasticizers a flexible, elastic plastic can
be made. This plastic has found extensive use as an electrical insulator for wires and cables.
Wood Based Panels
Usage: Wood-based panels shall be used as walls, floors, and ceiling for agricultural structures as
well as for machine structural purposes.
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Designations: Wood-based panels refer to a variety of different board products made from wood in
the form of chips, strips, veneers, strands or fibres. Examples of wood-based panels are particle
board, fibre board, plywood and oriented strand board (OSB).
Design Considerations:
Wood-based panels are classified as follows:
Adhesive Bonded Panels:
Plywood and Plyboard: Used for walls, floors, and ceilings in agricultural structures.
Fiberboard: Made of consolidated ligno-cellulosic fibers with inherent adhesive properties or
added resin.
Particleboard: Suitable for various structural purposes.
Cement Bonded Panels: For the purposes of this standard, the panels that shall be discussed under
cement bonded panels are as follows: a) Fiber cement flat sheets b) Wood wool cement bonded
boards