The document discusses shore hardness testing, which measures the resistance of materials to indentation. Shore hardness is measured using a durometer indenter that penetrates the sample, with higher numbers indicating greater resistance. The shore scale has two types - Shore A for softer rubbers and Shore D for harder materials. Shore hardness provides an empirical measure of indentation resistance but does not predict other material properties. Mohs hardness characterizes scratch resistance and was created by Friedrich Mohs using minerals to demonstrate increasing hardness.

2. For more help contact me

Muhammad Umair Bukhari
Engr.umair.bukhari@gmail.com
www.bzuiam.webs.com
03136050151

3. Introduction

 Shore hardness is a measure of the resistance of material
to indentation by 3 spring-loaded indenter.
 The higher the number, the greater the resistance.
 The shore scleroscope measures hardness in terms of the
elasticity of the material.
 A diamond-tipped hammer in a graduated glass tube is
allowed to fall from a known height on the specimen to
be tested, and the hardness number depends on the
height to which the hammer rebounds; the harder the
material, the higher the rebound

4. Indenter


5. Shore Test

 The Shore hardness is measured with an apparatus
known as a Durometer and consequently is also known
as “Durometer hardness”.
 The hardness value is determined by the penetration of
the Durometer indenter foot into the sample.
 Because of the resilience of rubbers and plastics, the
hardness reading my change over time - so the
indentation time is sometimes reported along with the
hardness number.
 The ASTM test number is ASTM D2240 while the
analogous ISO test method is ISO 868.

6. Shore Test

 The results obtained from this test are a useful
measure of relative resistance to indentation of
various grades of polymers.
 However, the Shore Durometer hardness test does
not serve well as a predictor of other properties such
as strength or resistance to scratches, abrasion, or
wear, and should not be used alone for product
design specifications.

7. Shore Scale

 Shore Scale is of two types:-
 Shore A
 Shore D
 The Shore A scale is used for “softer” rubbers while
the Shore D scale is used for 'harder' ones.

8. Shore A

 The shore A Hardness is the relative hardness of
elastic materials such as rubber or soft plastics can be
determined with an instrument called a “Shore
Durometer”.
 If the indenter completely penetrates the sample, a
reading of 0 is obtained, and if no penetration
occurs, a reading of 100 results. The reading is
dimensionless.

9. Shore Test Application

 The hardness testing of plastics is most commonly
measured by this test or Rockwell hardness test.
 Both methods measure the resistance of the plastic
toward indentation. Both scales provide an empirical
hardness value that doesn't correlate to other
properties or fundamental characteristics.

10. Shore Test Application

 Shore Hardness is the preferred method for rubbers/
elastomers.
 Shore Test is commonly carried out for polymers
such as:-
 Polyolefin
 Fluoropolymers
 Vinyls.

11. Mohs Scale

 The Mohs scale of mineral hardness characterizes
the scratch resistance of various minerals through
the ability of a harder material to scratch a softer
material.
 It was created in 1812 by the German geologist and
mineralogist Friedrich Mohs

12. Mohs Scale
Arrangement

 The Mohs scale of mineral hardness is based on the
ability of one natural sample of matter to scratch
another.
 The samples of matter used by Mohs are all minerals.
Minerals are pure substances found in nature. Rocks
are made up of one or more minerals.
 As the hardest known naturally occurring substance
when the scale was designed, diamonds are at the
top of the scale.

13. Mohs Scale
Arrangement

 The hardness of a material is measured against the
scale by finding the hardest material that the given
material can scratch, and/or the softest material that
can scratch the given material.
 For example, if some material is scratched by apatite
but not by fluorite, its hardness on the Mohs scale
would fall between 4 and 5.

14. Mohs hardness Mineral Chemical formula Absolute hardness Image
1 Talc Mg3Si4O10(OH)2 1
2 Gypsum CaSO4·2H2O 3
3 Calcite CaCO3 9
4 Fluorite CaF2 21
5 Apatite Ca5(PO4)3(OH–,Cl–,F–) 48

15. Mohs hardness Mineral Chemical formula Absolute hardness Image
6 Orthoclase Feldspar KAlSi3O8 72
7 Quartz SiO2 100
Al2SiO4(OH–,F–
8 Topaz 200
)2
9 Corundum Al2O3 400
10 Diamond C 1600

16. Mohs scale Non-
uniformity

 The Mohs scale is a purely ordinal scale. For
example, corundum (9) is twice as hard as topaz (8),
but diamond (10) is almost four times as hard as
corundum.