Home > Civil > Mechanical Properties of Material

Mechanical Properties of Material

What are the Mechanical Properties of Material?

The physical property that a material show on the applying of forces is called mechanical properties. To select the material for an engineering application, it is very essential to know the mechanical properties of the material.

Materials are divided into two types metals and non-metals. While metals have also two main types Ferrous and Non-ferrous metals. There is a lot of difference between ferrous and Non-ferrous metals.

Usually Ferrous metals carry iron and also other tiny materials. Ferrous metals are mostly used in the mechanical industry, while non-ferrous carry no iron and is manufactured from other materials like zinc, copper, magnesium and aluminum.

mechanical properties of material

There are different mechanical properties of materials most of people interchange these properties with each other but they are totally different. The mechanical properties of a material are given below:

  • Strength
  • Durability
  • Fatigue Strength
  • Brittleness
  • Stiffness
  • Hardness
  • Toughness
  • Embrittlement
  • Homogeneity
  • Isotropy
  • Anisotropy
  • Elasticity
  • Plasticity
  • Ductility
  • Malleability
  • Creep
  • Resilience
  • Damping
  • Thermal expansion
  • Mass diffusivity
  • Coefficient of restitution
  • Flexural strength
  • Poison’s ratio
  • Slip
  • Resilience
  • Specific weight
  • Stiffness
  • Viscosity
  • Surface roughness
  • Bulk Modulus
  • Young Modulus


The material that can bear the load before failure it is called strength of material. Those material who can bear more load we say that it has more strength. While for those material who can bear less force we say that this material has less strength. Based on load there are three types of strength that is given below:

  • Compressive strength
  • Shear strength
  • Tensile strength

Compressive strength:

Compressive strength is also known as compression strength it is the ability of a material to bear the loads. The load tends to reduce the size, as opposed to which bear loads tends to elongate. In simple words, the material resists when it is pushed together it is called its compressive strength.

Shear strength:

The strength of a material is against the failure of structure. when the material fails in shear. A shear force tends to causes a sliding failure. This sliding failure is parallel to the direction of the force.

Tensile strength:

Tensile strength can be defined as the max stress that a material can bear when it is pulled or stretched before breaking.

The max force that a material can bear without fracture when being stretched, divided by the actual area of the material. It has dimensions of load per unit area and in the English system of measurement are commonly indicate in units of pounds per square inch, usually it is abbreviated in psi. When the stresses less than the tensile strength are removed, the original shape and size of material can return either completely or partially.

There are three types of strength based on deformation before fracture. The types of strength based on deformation is given below:

  • Elastic strength
  • Ultimate strength
  • Yield strength

Elastic strength:

It is the ability of material to absorb, store, and release energy. The ability of a material to come back to its original shape after stress is released. In most of materials, the relation between stress and strain is directly proportional (up to a fixed limit), the relation between these two terms in graph is representing in a straight line.


Ultimate strength:

It is the max stress that a material can bear before it breaks or weakens. For instance, the ultimate strength of tensile for AISI 1018 Steel is 440 MPa. In Imperial units, the unit of stress is given as pounds’ force per square inch. This unit is usually abbreviated as psi.

Yield strength:

Yield strength is the amount of stress (Yield point) that a material can withstand before moving from elastic deformation into plastic deformation. Yield Point is in mild or medium carbon steel the stress at which a marked increase in deformation appear without increase in load.

Fatigue Strength:

Fatigue strength is the amount of cycles a material can bear under stress (cyclic loading) upon coming to failure. The magnitude of cyclic stress that can be exerted to a material without failure. life of fatigue is the cycles number of a stress level that a material will survive.


In Brittleness when a material breaks suddenly because of stress, without elastic deformation or changes in dimension. For example, glass, ceramics, marble. If load is applying on the brittle material it breaks suddenly without any deformation or changes in volume.


Stiffness is the ability of material to resist major elastic deformation while load is applied on material. The less deformation a material indicates at the time of applied load, it is stiffer.


Hardness is the ability of material to resist different forms of deformation, depression and penetration. It is referring to its resistance to scratching, scraping, drilling, chipping and wear and tear.


Toughness is the capacity of material to bear elastic and plastic deformation without any failure. usually toughness is measured by the amount of energy a material can absorb before fracturing.


When metal losings its ductility and becoming brittle because of physical changes or chemical changes. The example of embrittlement is Hydrogen embrittlement, temper embrittlement, liquid metal embrittlement, and sulfide stress cracking (SSC). 


Homogeneity is property of material in which a material has the same properties throughout its whole geometry.

These materials cannot be separated mechanically or recognize individually. The example of homogeneity materials is metals, glass, shampoo, cleaner, steel paper, plastics, polypropylene resins, yarn, coatings and nylon.


The material having identical property in all directions. The example of isotropic material is Glass and metals.

Most of people confused with these two terms homogeneity and isotropic materials but they are different from each other isotropic materials show the same properties in all direction, while homogeneous materials have the same properties without of direction.

In isotropic material the Diffusion is same in every direction.


In anisotropy the material show different properties based on its direction. The example of anisotropy is computer graphics, surface of anisotropic changes in appearance depending on the angle displayed at.


In elasticity the Materials that return back to their previous dimensions after deformation. All materials have a specific elastic limit before permanently deformed, it is known as plasticity deformation.


Plasticity is a permanent deformation that happens by stress before the failure. Typically, plasticity is used in metal shaping to get specific shapes and forms.


Ductility is the property of material in which a solid material becoming stretched because of tensile stress. Ductility is mostly use in the process of turning the metal into wiring. The ductility materials are silver, gold, copper, erbium, samarium, and terbium etc.


Malleability is the ability to plastically deform a material or change its shape without fractured. The example of malleability materials is gold, iron, aluminum, copper, silver, and lead. While Gold and silver is high malleable materials.


Machinability is the property of material in which a metal part can be cut without affect the quality of the finish. The example of machinability materials is steel, steel has the best machinability with presence of carbon, and also 0.20% Chromium.


Creep is the property of material in which a deformation is very slow (or change in dimensions) of materials by a specific load. Creep is Measured by the effect of time and temperature. usually happens at high temperatures, but can also happens at room temperature. The example of creep is Plastics and low melting temperature metals, plus many solders, can start creep at room temperature. Glacier flow is also the example of creep. 


Resilience is the ability to absorb energy when a material is elastically deformed, and releasing that energy after being let go. before permanent deformation resilience is the maximum energy a material can absorb. 


Damping is the amount of energy used to cause vibration, oscillation or stress. The example of damping material is cast iron A material with a good damping property, such as cast iron, is capable of absorbing high amounts of vibration.

Thermal Expansion:

It is the change in shape, volume or area cause by changes in temperature.

Thermal expansion coefficient refers to the shape or size of material will change at the time of exposure to a change in temperature.

There are three types of thermal expansion that is given below:

  • Linear Expansion
  • Superficial Expansion
  • Cubical Expansion.

Linear Expansion:

It is type of thermal expansion in which change in one dimension (length) as against to change in volume (volumetric expansion). the change in length measurements of an object because of thermal expansion is related to temperature change by a coefficient of linear thermal expansion.

Superficial Expansion:

 Superficial Expansion is the extension in area of a tabular surface because of heating is called superficial expansion. superficial expansion coefficient is the ratio of increase in area to its actual area for every degree increase in temperature.

Cubical Expansion:

Cubical expansion is the Increase in volume of a body on heating. It is also known as “volumetric expansion”. For example, a metallic body of volume = V1. Let its temperature T is increase. So the Increase in volume (V) is directly proportional to its previous volume (V1) and increase in temperature (T).

Mass Diffusivity:

It is constant proportionality between the molar flux because of molecular diffusion and gradient in the concentration of the species. Diffusivity is experience in Fick’s law and also other physical chemistry equations.

The SI unit of mass Diffusivity is m2/s (length2 / time). In CGS units it is given in cm2/s.

coefficient of Restitution:

It is the ratio of the final velocity to initial velocity between two objects after they strike. It is denoted by (e). Coefficient of Restitution is ranges from 0 to 1. the 1 is a perfectly elastic collision.  While 0 is perfectly inelastic collision. Coefficient of restitution is measured in the Leeb rebound hardness test, it is expressed as 1000 times the coefficient of restitution, but it is only a proper coefficient of restitution for the test.

Flexural strength:

In a flexure test the stress in a material before it yields is called flexural strength It is also known as modulus of rupture, or bend strength, or transverse rupture strength is a material property. The formula for measuring flexural strength is given:

σ = 3FL/2bd2

F is the force at the fracture point (N)

L is the length of the support span

b is width

d is depth or thickness

Poison’s ratio:

Poisons ratio is a measure of the Poisson effect, in poisons ratio a material tending to enlarge in directions perpendicular to the compression direction. Vice versa if the material is compressed less than stretching, it will shrink in the directions horizontally to the direction of stretching.  

Poisons ratio = lateral strain / longitudinal strain

Poisons ratio is represented by µ.

S.No Material Poisson’s Ratio
1 Gold 0.42 to 0.44
2 Rubber 0.5
3 Clay 0.40 to 0.49
4 Magnesium 0.25 to 0.28
5 Titanium 0.26 to 0.34
6 Aluminum alloy 0.32
7 steel 0.27 to 0.30
8 cast iron 0.21 to 0.26
9 copper 0.33
10 concrete 0.1 to 0.2
11 cork 0
12 foam 0.1 to 0.50
13 glass 0.18 to 0.3
14 sand 0.2 to 0.45


Slip is sliding displacement on a plane of one part of a crystal to the rest of the crystal on the shearing force that is, forces applied parallel to that plane. Most of the permanent, or plastic, deformation of materials because of stress is the result of slip within the separate crystals that begin the material.

Specific weight:

The weight per unit volume of a material is called specific weight. It is also called unit weight. Typically value of specific weight of water is used on Earth at 4°C, which is 9.807 kN/m3 or 62.43 lbf/ft3. less specific weight is used for relative density.


It is a resistance to deformation at a given rate for fluid is called viscosity. For liquids, it signifies to the concept of “thickness”: for example, syrup or honey has a higher viscosity than water.

The SI unit of viscosity is the Newton sec per meter square (N s/m2), viscosity also find in the Pascal second (Pa – s) and kilogram per meter per second (kg/m·s). The CGS unit of viscosity is the poise (P, or g/cm-s)

Surface roughness:

It is mostly shortened to roughness. surface roughness is a part of surface texture. It is measure by the variation in the direction of the ordinary vector of a actual surface from its ideal form. If these variations are large, the surface is rough; if they are small, the surface is smooth.

Bulk Modulus:

In bulk modulus we measure the resistant to compression of material that how much it will resist the compression. It is the ratio of the tiny pressure increase to the resulting decrease of the volume. the substance response (strain) to the stress: the shear modulus explains the response to shear, and Young’s modulus explains the response to linear stress. For a fluid, only one the bulk modulus is useful. For a compound anisotropic solid like wood and paper etc. these moduli it means all of three moduli do not contain sufficient information to explain their behavior, so I this case Hooke’s law is used.

The bulk modulus K>0 can be properly defined by the given equation

K= -V dP/dV

where P is pressure,

 V is volume,

 dP/dV denotes the derivative of pressure with volume.

 In view of unit mass,

k = ρ dp/ dv


ρ is density

dP/dρ denotes the derivative of pressure with density.

If the bulk modulus is inverse it gives a materials compressibility.

Young Modulus:

Young modulus measures the stiffness of a material (solid material). It is the relationship between stress and strain in a material in the elasticity mechanism of a uniaxial deformation.

Young’s modulus is named after the Thomas Young was British scientist in 19th-century who discover Young modulus property of material but this concept of young modulus was firstly developed in 1727 by Leonhard Euler, the first experiments that used the concept of this Young’s modulus. The term modulus is derived from the Latin. The term modulus means measure.

you may read more:



Leave a Reply

Your email address will not be published. Required fields are marked *