Resistance of a mineral to scratching, determined on a comparative basis by the Mohs scale .

Old English heardnes; see hard (adj.) + -ness. Meaning "difficulty of action or accomplishment" is late 14c.

The resistance of an object to scrapes and scratching. The harder it is, the greater its resistance. (See Hardness in Mineral Properties for more information.)

quality of water mostly caused by excess Calcium and Magnesium

definition – quality of water mostly caused by amounts of Calcium and Magnesium. See KH, pH, and alkalinity for more information.

The resistance of a substance to surface abrasion.

The quality of metal that describes resistance to denting, scratching, or bending.

resistance to indentation. See Durometer hardness.

Resistance to indentation, scratching, abrasion, or cutting. Materials with little resistance are called soft; those with high resistance are called hard. Hardness in steel is measured by scientific i [..]

Defined in terms of the method of measurement. 1. Usually the resistance to indentation. 2. Stiffness or temper of wrought products. 3. Machinability characteristics.

A water-quality indication of the concentration of alkaline salts in water, mainly calcium and magnesium. If the water you use is "hard" then more soap, detergent or shampoo is necessary to raise a lather.

That property of the wood species or dried film of finishing material that causes it to withstand denting or being marked when pressure is exerted on its surface by an outside object or force.

Resistance of a material to indentation as measured by such methods as Brinell, Rockwell, and Vickers. The term hardness also refers to stiffness of a material, or its resistance to scratching, abrasi [..]

A quality of stone determined by ASTM C241 test.

The resistance of a mineral to scratching.

a water-quality indication of the concentration of alkaline salts in water, mainly calcium and magnesium. If the water you use is "hard" then more soap, detergent or shampoo is necessary to raise a lather.

chemistry - the sum of divalent ions in a water sample, usually calculated as calcium + magnesium, and often reported in mg/L as CaCO3

The resistance of a mineral to scratching.

Property of a mineral's resistance to being scratched.

Measurement of the resistance to penetration of an indenture into a cured rubber sample. Heat Aging: Loss of physical properties as a result of exposure to heat. Heat Resistance: Rubber compounds capacity to undergo exposure to some specified level of elevated temperature and retain a high level of its original properties. Heteropolymer: polymer co [..]

 – The ability of a cured coating to withstand indentation.

See toughness

The ability of a metal to resist penetration, defined in terms of the measurement (Brinell, Rockwell, etc.).

The peak force that results from a sample being compressed to a given distance, time, or % of deformation, representing the firmness (or softness). One of the eight fundamental mechanically-derived texture-influencing attributes - one of the five primary parameters. In consumer (sensory) terminology, a texture with solidity and brittleness.

(n) the property of being rigid and resistant to pressure; not easily scratched; measured on Mohs scale(n) a quality of water that contains dissolved mineral salts that prevent soap from lathering(n)  [..]

A physical property test that identifies the strength of a mineral (Lesson 27)

Measured in terms of Rockwell or Brinell. Shows resistance of a fastener to rough marks and abrasions. Also can indicate yield/tensile and brittleness of a fastener. However, for stainless the correla [..]

a characteristic of water determined by the levels of calcium and magnesium

rigor

A measure of a mineral’s resistance to scratching. The hardness of a mineral is measured by scratching it against another substance of known hardness. headland

The measure of how resistant a gemstone is to being scratched. The Mohs Scale of hardness ranges from 1 to 10, with 10 being the hardest. Diamonds are rated 10 on the Mohs Scale

 The resistance of a material to deformation, particularly permanent deformation, indentation, or scratching.

Degree to which a metal will resist cutting, abrasion, penetration, bending and stretching. The indicated hardness of metals will differ somewhat with the specific apparatus measuring hardness. (See B [..]

A measure of a mineral's resistance to scratching. The hardness of a mineral is measured by scratching it against another substance of known hardness.

ability to resist wear or indentation.

The relative resistance of a metal to denting, scratching, or bending. Hardness of metallic shafts is typically expressed as a relative value from the Rockwell C or Brinell hardness scales.

Resistance of metal to plastic deformation, usually by indentation. However, the term may also refer to stiffness or temper, or to resistance to scratching, abrasion, or cutting. Indentation hardness [..]

The relative resistance of a mineral to scratching, as measured by the Mohs' scale. The relative resistance of a metal to denting, scratching or bending. Hardwired Signals Electrical signals betw [..]

Is a measure of the resistance of a material to scratching and indention.

a measure of the amount of calcium and magnesium salts in water. Usually expressed as grains per gallon or ppm as caco3.

is the resistance of a material to deformation, particularly permanent deformation, indentation or scratching.

A property that causes the material to resist indentation or abrasion.

See all hardness related definitions A measured factor that reasonably predicts the amount metal will resist abrasion and bending, as well as indicating Ultimate Strength. Most commonly expressed as Brinell Hardness and Rockwell Hardness. ASTM E140 provides a guide for comparing hardness determined by different methods and expressed on different [..]

a characteristic of water, imparted by salts of calcium, magnesium, and iron, such as bicarbonates, carbonates, sulfates, chlorides, and nitrates that cause curdling of soap, deposition of scale in bo [..]

Hardness is a measure of how easily you can scratch a substance. Diamonds have a greater hardness than copper sulfate crystals. Copper sulfate is softer than a diamond. More Information: Solids

The sum of the calcium and magnesium concentrations, expressed as calcium carbonate (CaCO3) in milligrams per liter. Excessive hardness results in excessive use of soaps and detergents and causes the [..]

Resistance of a mineral to abrasion or scratching. Hare Jackrabbits. They differ from rabbits in having generally larger ears, tail, and legs. HCN High Country News.

The hardness of a water is a measure of the concentration of the multivalent cations (positively charged particles) in the water, but primarily it is equivalent to the calcium and magnesium concentration of the water. Hardness is typically reported as mg /L as CaCO3 (calcium carbonate), but it may also be reported as grains per gallon (1 gpg (US) = [..]

The mechanical property of material that determines its resistance to force. Hardness Tests measure this property.

Also called "calcium hardness." The amount of dissolved minerals (mostly calcium and magnesium) in a body of water. In unbalanced water, high levels cause scale and low levels corrode surfac [..]

The resistance of a material to compression and indentation.

A measure of how hard or soft a mineral is relative to diamond, the hardest mineral on the 10-point Mohs scale of hardness.

the host rock that a mineral specimen or crystal is found in or on, bedrock

Water's component of soluble calcium and magnesium salts equals water) hardness. It is usually expressed in terms of calcium carbonate equivalents. Some calcium in the brewing water is desirable [..]

is the measure of the amount of certain dissolved minerals in water, particularly calcium and magnesium. Hardness is the property in water that causes excessive soap consumption and encrustation in bo [..]

A characteristic of water caused mainly by the salts of calcium and magnesium, such as bicarbonate, carbonate, sulfate, chloride, and nitrate. Excessive hardness in water is undesirable because it cau [..]

The quality of water primarily caused by excess calcium and magnesium concentration.

The tendency of a water to form scale or soap scum due to the presence of dissolved minerals, primarily calcium and magnesium.

Calcium and magnesium are the main hardness minerals. Although hardness is not a health threat, excessive levels may be harmful to plumbing fixtures and pipes. White deposits around faucets and on dis [..]

This is a characteristic of natural water due to the presence of dissolved calcium and magnesium. Hardness is usually expressed in grains per gallon, parts per million, or milligrams per liter, all as calcium carbonate equivalent. Water up to 1 GPG (or 17.1 mg/l) is considered soft, and water from 60 to 120 ppm is considered moderately hard. A wate [..]

The amount of calcium and magnesium dissolved in water epxressed as ppm. High Dissolved Solids

A water-quality indication of the concentration of alkaline salts in water, mainly calcium and magnesium. If the water you use is "hard" then more soap, detergent or shampoo is neces [..]

The concentration of calcium or magnesium in water; affects the availability of nutrients and toxic substances to stream organisms.

A characteristic of natural water due to the presence of dissolved calcium and magnesium. Hardness is usually expressed in grains per gallon, parts per million or milligrams per litre, all as calcium [..]

Hardness is the resistance of a mineral to abrasion or scratching.

The resistance of a mineral surface to being scratched by an object of known hardness. Hardness is measured on the Mohs scale of hardness which defines the scale of hardness with ten common minerals ( [..]

The resistance of an object to scrapes and scratching. The harder it is, the greater its resistance. (See Hardness in mineral properties for more information.)

See Mohs' hardness scale.

The ability to resist abrasion.

The resistance to abrasion of a mineral when a pointed fragment of another substance is drawn across it without sufficient pressure to develop cleavage.

condition caused by dissolved salts of calcium, magnesium, and iron, such as bicarbonates, carbonates, sulfates, chlorides, and nitrates.

the amount of calcium carbonate dissolved in water.

the resistance of a substance to surface abrasion.

a measure of the ability of a mineral to resist scratching

A measure of soap-neutralizing ions present in water; predominantly magnesium and calcium , but other alkali metal ions contribute to the effect.

Measure of a material's resistance to localized plastic deformation. Most hardness tests involve indentation, but hardness may be reported as resistance to scratching (file test), or rebound of a projectile bounced off the material (scleroscope hardness). Some common measures of indentation hardness are Brinell Hardness Number, Rockwell Hardne [..]

When hard water is used with soap it will form an insoluble residue and hard water will form a scale in utensils in which the water has been allowed to evaporate. Hardness is mainly caused by calcium and magnesium ions. Hardness is generally expressed in mg/L calcium carbonate (Ca CO3).

Are generally referred to the presence of calcium and magnesium content of the water.

The scale-forming and lather-inhibiting qualities which water, high in calcium and magnesium ions, possesses.

Hardness is a measure of the resistance to localized plastic deformation induced by either mechanical indentation or abrasion. Some materials (e.g. metals) are harder than others (e.g. plastics, wood) [..]