en.wikipedia.org/wiki/Hardness Hardness is a measure of how resistant solid matter is to various kinds of permanent shape change when a compressive force is applied. Some materials, such as metal, are harder than others.
www.merriam-webster.com/dictionary/hardness Full Definition of HARDNESS 1 : the quality or state of being hard 2 a : the cohesion of the particles on the surface of a mineral as determined by its capacity to scratch another or be itself scratched — compare mohs' scale b : resistance of metal to indentation under a static load or to ...
dictionary.reference.com/browse/hardness noun 1. the state or quality of being hard: the hardness of ice. 2. a relative degree or extent of this quality: wood of a desirable hardness. 3. that quality in water that is imparted by the presence of dissolved salts, especially calcium sulfate or bicarbonate. 4. unfeelingness or jadedness; callo
en.wikipedia.org/wiki/Scratch_hardness Scratch hardness tests are used to determine the hardness of a material to scratches and abrasion. The earliest test was developed by mineralogist Friedrich Mohs in 1820 (see Mohs scale). It is based on relative scratch hardness, with talc assigned a value of 1 and diamond assigned a value of 10 ...
www.galleries.com/minerals/property/hardness.htm A good property in mineral identification is one that does not vary from specimen to specimen. In terms of reliability, hardness is one of the better physical properties for minerals.
webmineral.com/help/Hardness.shtml Definition . Hardness is measured by the resistance which a smooth surface offers to abrasion. The degree of hardness is determined by observing the comparative ease or difficulty which which one mineral is scratched by another.
geology.com/minerals/mohs-hardness-scale.shtml One of the most important tests for identifying mineral specimens is the Mohs Hardness Test. This test compares the resistance of a mineral to being scratched by ten reference minerals known as the Mohs Hardness Scale (see Table 1).
https://www.nde-ed.org/.../Materials/Mechanical/Hardness.htm... Hardness. Hardness is the resistance of a material to localized deformation. The term can apply to deformation from indentation, scratching, cutting or bending.
www.britannica.com/EBchecked/topic/255101 hardness, resistance of a mineral to scratching, described relative to a standard such as the Mohs hardness scale. Hardness is an important diagnostic property in mineral identification.
www.businessdictionary.com/definition/hardness.html 1.Resistance of a material to deformation, indentation, or penetration by means such as abrasion, drilling, impact, scratching, and/or wear, measured by hardness tests such as Brinell, Knoop, Rockwell, or Vickers.
water.mecc.edu/exam_prep/hardness.html The degree of hardness acceptable for a finished water varies with the consumer or industry served. In 1968, the American Water Works Association (AWWA) established a water quality goal for total hardness of 80 to 100 mg/l as calcium carbonate.
www.yourdictionary.com/hardness You get used to knowing the different types of hardness and thickness. The hardness came back into his eyes and he looked away. His warm hands covered hers and she could feel the hardness of his chest muscles on her back as he guided her arms in a smooth swing.
www.britannica.com/EBchecked/topic/387714 Mohs hardness, rough measure of the resistance of a smooth surface to scratching or abrasion, expressed in terms of a scale devised (1812) by the German mineralogist Friedrich Mohs.
www.kidsloverocks.com/html/mineral_hardness.html Mineral Hardness . The hardness of a mineral is a way of describing how easy or difficult it is to scratch the mineral. It is used, in combination with the other physical properties, to help identify a mineral specimen.
www.bestcrystals.com/hardness.html Information about the Mohs Scale of Hardness for rock classification. The Mohs sacale consists of 10 classifications of hardness. Chart listing stones and property descriptions for each hardness classification.
www.fcwa.org/water/hardness.htm Many industrial and domestic water users are concerned about the hardness of their water. Hard water requires more soap and synthetic detergents for home laundry and washing, and contributes to scaling in boilers and industrial equipment.
www.worldoftest.com/hardnesstester.htm Hardness Tester Range - Qualitest offers more than 100 models of advanced portable and bench-top hardness testing equipment such as Rockwell hardness tester, Universal hardness testers, Brinell hardness testers, Vickers, Micro, Knoop hardness testers and hardness test blocks.
engineersedge.com/material_science/hardness.htm Strength / Mechanics of Materials Table of Content. Material Hardness Review. Hardness is the property of a material that enables it to resist plastic deformation, penetration, indentation, and scratching.
chemistry.about.com/od/geochemistry/a/mohsscale.htm The Mohs Scale of Hardness measures how well a substance resists scratching by another material. You can use this scale to test the hardness of rocks, minerals, and crystals, to help identify them.
www.minsocam.org/MSA/collectors_corner/article/mohs.htm The Mohs' hardness scale was developed in 1822 by Frederich Mohs. This scale is a chart of relative hardness of the various minerals (1 - softest to 10 - hardest).
www2.ca.uky.edu/wkrec/HARDNESS.htm Water hardness is important to fish culture and is a commonly reported aspect of water quality. It is a measure of the quantity of divalent ions (for this discussion, salts with two positive charges) such as calcium, magnesium and/or iron in water.
medical-dictionary.thefreedictionary.com/hardness Definition of hardness in the Medical Dictionary. hardness explanation. Information about hardness in Free online English dictionary. What is hardness? Meaning of hardness medical term. What does hardness mean?
www.menshealth.com/health/hardness-factor When the penis is hard, life is good. When hardness diminishes, so does a man's health and his innate sense of who he is. No matter how talented a man may feel he is in bed, he defines his sex by his erection, by its strength and hardness.
encyclopedia2.thefreedictionary.com/hardness hardness, property of matter commonly described as the resistance of a substance to being scratched by another substance. The degree of hardness is relative, different substances being compared with one another.
water.me.vccs.edu/courses/ENV211/lab6_print.htm Since the hardness in water primarily originates from contact with the soil and with rock formations, hard waters tend to originate in areas where topsoil is thick and limestone formations are present.
www.purewateroccasional.net/wtihardness.html Hardness in water is determined by the content of calcium and magnesium salts. These salts are formed when calcium and magnesium combine with bicarbonates, sulfates, chlorides, and nitrates.
www.hardwoodinstaller.com/preparation/hardness.htm Hardwood Flooring Hardness Chart. Having seen changes in the wood flooring business over the years, I never realized how many people were ill-advised of how to actually go about buying wood floors.
water.usgs.gov/edu/hardness.html The simple definition of water hardness is the amount of dissolved calcium and magnesium in the water. Hard water is high in dissolved minerals, both calcium and magnesium.
www.advantagelumber.com/janka.htm The Janka Hardness Test is a measure of the hardness of wood. The Janka Test was developed as a variation of the Brinell hardness test. The test measures the force required to push a steel ball with a diameter of 11.28 millimeters (0.444 inches) into the wood to a depth of half the ball’s ...
www.stewartfloor.com/resources/janka-hardness-chart The Janka hardness table shows you whether a certain type of wood is suitable for flooring. The Janka Hardness Test measures a wood's resistance to denting or crushing.
www.oringsusa.com/html/durometer_of_o-rings.html The hardness of rubber compounds is measured by the Shore A durometer; the higher the durometer, the harder the compound. 70-durometer hardness should be used whenever possible as it offers the best combination of properties for most O-Rings applications.
www.thefreedictionary.com/Hardness+(materials+science) hard·ness (härd′nĭs) n. 1. The quality or condition of being hard. 2. The relative resistance of a mineral to scratching, as measured by the Mohs scale. 3. The relative resistance of a metal or other material to denting, scratching, or bending. hardness (ˈhɑːdnɪs) n 1. the quality or ...
nhml.com/hardness-testing.cfm Hardness Testing. 7/1/2002 by Fred Hochgraf. Background. In metal working, hardness generally implies resistance to penetration. It may, however, include resistance to scratching, abrasion or cutting.
sizes.com/units/hardness_rockwell.htm A scale indicating the hardness of materials, first used in 1919, when it was invented by Stanley P. Rockwell. The measurement has no units. The symbol is HR followed by a letter indicating one of a number of possible scales, described in the table below.