Brinell scale

The Brinell scale /brəˈnɛl/ characterizes the indentation hardness of materials through the scale of penetration of an indenter, loaded on a material test-piece. It is one of several definitions of hardness in materials science.

Proposed by Swedish engineer Johan August Brinell in 1900, it was the first widely used and standardised hardness test in engineering and metallurgy. The large size of indentation and possible damage to test-piece limits its usefulness. However it also had the useful feature that the hardness value divided by two gave the approximate UTS in ksi for steels. This feature contributed to its early adoption over competing hardness tests.

The typical test uses a 10 mm (0.39 in) diameter steel ball as an indenter with a 3,000 kgf (29.42 kN; 6,614 lbf) force. For softer materials, a smaller force is used; for harder materials, a tungsten carbide ball is substituted for the steel ball. The indentation is measured and hardness calculated as:

where:

BHN = Brinell Hardness Number (kgf/mm2)
P = applied load in kilogram-force (kgf)
D = diameter of indenter (mm)
d = diameter of indentation (mm)

Brinell hardness is sometimes quoted in megapascals; the Brinell hardness number is multiplied by the acceleration due to gravity, 9.80665 m/s2, to convert it to megapascals. The BHN can be converted into the ultimate tensile strength (UTS), although the relationship is dependent on the material, and therefore determined empirically. The relationship is based on Meyer's index (n) from Meyer's law. If Meyer's index is less than 2.2 then the ratio of UTS to BHN is 0.36. If Meyer's index is greater than 2.2, then the ratio increases.[1]

BHN is designated by the most commonly used test standards (ASTM E10-14[2] and ISO 6506–1:2005[3]) as HBW (H from hardness, B from brinell and W from the material of the indenter, tungsten (wolfram) carbide). In former standards HB or HBS were used to refer to measurements made with steel indenters.

HBW is calculated in both standards using the SI units as

where:

F = applied load (Newtons)
D = diameter of indenter (mm)
d = diameter of indentation (mm)
BrinellHardness
Force diagram

Common values

When quoting a Brinell hardness number (BHN or more commonly HB), the conditions of the test used to obtain the number must be specified. (HB is not related to the "HB" degree of pencil hardness.) The standard format for specifying tests can be seen in the example "HBW 10/3000". "HBW" means that a tungsten carbide (from the chemical symbol for tungsten or from the Swedish/German name for tungsten, "Wolfram") ball indenter was used, as opposed to "HBS", which means a hardened steel ball. The "10" is the ball diameter in millimeters. The "3000" is the force in kilograms force.

The hardness may also be shown as XXX HB YYD2. The XXX is the force to apply (in kgf) on a material of type YY (5 for aluminum alloys, 10 for copper alloys, 30 for steels). Thus a typical steel hardness could be written: 250 HB 30D2. It could be a maximum or a minimum.

Correspondent relations among scale, indenter and test force:
Hardness symbol Diameter of Indenter

mm

F/D2 Test force

N/kgf

HBW 10/3000 10 30 29420(3000)
HBW 10/1500 10 15 14710(1500)
HBW 10/1000 10 10 9807(1000)
Brinell hardness numbers
Material Hardness
Softwood (e.g., pine) 1.6 HBS 10/100
Hardwood 2.6–7.0 HBS 1.6 10/100
Lead 5.0 HB (pure lead; alloyed lead typically can range from 5.0 HB to values in excess of 22.0 HB)
Pure Aluminium 15 HB
Copper 35 HB
Hardened AW-6060 Aluminium 75 HB
Mild steel 120 HB
18–8 (304) stainless steel annealed 200 HB[4]
Hardox wear plate 400-700 HB
Hardened tool steel 600–900 HB (HBW 10/3000)
Glass 1550 HB
Rhenium diboride 4600 HB
Note: Standard test conditions unless otherwise stated

Standards

See also

(Multi use Hardness Test)

References

Notes

  1. ^ Tabor, p. 17.
  2. ^ ASTM E10 – 14 Standard Test Method for Brinell Hardness of Metallic Materials
  3. ^ ISO 6506–1:2005 Metallic materials – Brinell hardness test – Part 1: Test method
  4. ^ 304: the place to start, retrieved 2009-03-31.

Bibliography

External links

Arbor milling

Arbor milling is a cutting process which removes material via a multi-toothed cutter. An arbor mill is a type of milling machine characterized by its ability to rapidly remove material from a variety of materials. This milling process is not only rapid but also versatile.

Brinelling

Brinelling is the permanent indentation of a hard surface. It is named after the Brinell scale of hardness, in which a small ball is pushed against a hard surface at a preset level of force, and the depth and diameter of the mark indicates the Brinell hardness of the surface. Brinelling is a process of wear in which similar marks are pressed into the surface of a moving part, such as bearings or hydraulic pistons. The brinelling is usually undesirable, as the parts often mate with other parts in very close proximity. The very small indentations can quickly lead to improper operation, like chattering or excess vibration, which in turn can accelerate other forms of wear, such as spalling and galling.

Cast iron

Cast iron is a group of iron-carbon alloys with a carbon content greater than 2%. Its usefulness derives from its relatively low melting temperature. The alloy constituents affect its colour when fractured: white cast iron has carbide impurities which allow cracks to pass straight through, grey cast iron has graphite flakes which deflect a passing crack and initiate countless new cracks as the material breaks, and ductile cast iron has spherical graphite "nodules" which stop the crack from further progressing.

Carbon (C) ranging from 1.8 to 4 wt%, and silicon (Si) 1–3 wt% are the main alloying elements of cast iron. Iron alloys with lower carbon content (~0.8%) are known as steel. While this technically makes the Fe–C–Si system ternary, the principle of cast iron solidification can be understood from the simpler binary iron–carbon phase diagram. Since the compositions of most cast irons are around the eutectic point (lowest liquid point) of the iron–carbon system, the melting temperatures usually range from 1,150 to 1,200 °C (2,100 to 2,190 °F), which is about 300 °C (540 °F) lower than the melting point of pure iron of 1,535 °C (2,795 °F).

Cast iron tends to be brittle, except for malleable cast irons. With its relatively low melting point, good fluidity, castability, excellent machinability, resistance to deformation and wear resistance, cast irons have become an engineering material with a wide range of applications and are used in pipes, machines and automotive industry parts, such as cylinder heads (declining usage), cylinder blocks and gearbox cases (also declining usage). It is resistant to destruction and weakening by oxidation.

The earliest cast-iron artifacts date to the 5th century BC, and were discovered by archaeologists in what is now Jiangsu in China. Cast iron was used in ancient China for warfare, agriculture, and architecture. During the 15th century, cast iron became utilized for cannon in Burgundy, France, and in England during the Reformation. The amounts of cast iron used for cannon required large scale production. The first cast-iron bridge was built during the 1770s by Abraham Darby III, and is known as The Iron Bridge. Cast iron was also used in the construction of buildings.

Cupules

Cupules () are humanly made depressions on rock surfaces that resemble the shape of a spherical cap or dome. They were made by direct percussion with hand-held hammer-stones, on vertical, sloping or horizontal rock panels. Cupules are the world's most common rock art motifs, occurring in huge numbers in every continent except Antarctica. They were produced in many cultures, from the Lower Paleolithic to the 20th century, and they can be found on most lithologies. Similar artifacts from lithic Native American cultures are also known as cupstones.

The name cupule derives from the Late Latin cūpula, “little cask”. These features are usually between 1.5 and 10 cm in diameter, although larger specimens are occasionally seen. They occur commonly in groupings that may number several hundred; they may be arranged in geometric formations, such as aligned sets, or they occur in unstructured, random groups. Some specimens in the southern Kalahari Desert are suggested to be in the order of 410,000 years old, and those of two sites in central India should be even earlier. In Middle Paleolithic or Middle Stone Age contexts, cupules occur in Africa and Australia, and are attributable to that era also in Europe. They seem to become less common in the course of the European Upper Paleolithic, but still occur occasionally. Cupules are extremely common in the Neolithic and the Metal Ages of Europe, Asia and Africa, and in medieval Europe.

Surprisingly little is known about the purpose or significance of cupules. Many meanings or purposes have been suggested in the literature (one review lists 71). In a number of cases cupules were demonstrated to mark specific rocks used as lithophones; in some cases they served in board games; but other credible ethnographic interpretations of their former cultural functions have been secured in very few instances. These cannot necessarily be extrapolated to other corpora, which are widely separated temporally as well as spatially. Even the identification of cupules remains tenuous: archaeologists have encountered difficulties in distinguishing cupules from other features, such as potholes, mortars, querns, metates, tacitas, and small solution pans.

Typically cupules were created by direct percussion, i.e. using hand-held hammer-stones. Replication studies have shown that the time required for their production varies greatly, depending on the rock type. It can take one minute to create a 12 mm deep cupule on weathered sandstone, but 45,000 and 60,000 hammer-stone strokes on unweathered quartzite. The resistance of a rock to kinetic impact is determined by its hardness, toughness and strength. Hardness, in this context, is a complex articulation of several factors, essentially a measure of how resistant rock is to various kinds of permanent shape change when a compressive force is applied to it. These factors include scratch or abrasion resistance (Rosiwal scale), toughness, strength, ductility, indentation hardness (measured by the Brinell scale and expressed in BHN, or measured by the Vickers test and expressed in kg/mm²) and brittleness factor. Abrasion hardness, indentation hardness and brittleness factor (ratio of the uniaxial compressive strength and the uniaxial tensile strength) combine to determine the “composite hardness index” θ, which governs the production coefficient ρ:

ρ = V θ²

The approximate cupule volume V is determined by:

V = π × d × (R² + r² + R × r) ⁄ 3

in which r = mean radius at rim and d = cupule depth. The mean radius is close to half the sum of two radii measured at right angles to each other. The kinetic energy applied in the production of cupules can be determined experimentally, kinetic energy Ek being the ability of a mass in motion to have a physical effect:

Ek = M v²

in which M = quantity of mass in motion, v = velocity in straight line. It amounts to tens of kilo-Newtons in the case of unweathered quartzite. This cumulative application of focused force has occasionally led to kinetic energy metamorphosis in sedimentary siliceous rocks, a phenomenon first identified in cupules but since recognized in many geological contexts.

Engineering drawing abbreviations and symbols

Engineering drawing abbreviations and symbols are used to communicate and detail the characteristics of an engineering drawing. This list includes abbreviations common to the vocabulary of people who work with engineering drawings in the manufacture and inspection of parts and assemblies.

Technical standards exist to provide glossaries of abbreviations, acronyms, and symbols that may be found on engineering drawings. Many corporations have such standards, which define some terms and symbols specific to them; on the national and international level, ASME standard Y14.38 is one of the widely used standards.

Jump to: 0-9 • A • B • C • D • E • F • G • H • I • J • K • L • M • N • O • P • Q • R • S • T • U • V • W • X • Y • Z • see also

Jump to: 0-9 • A • B • C • D • E • F • G • H • I • J • K • L • M • N • O • P • Q • R • S • T • U • V • W • X • Y • Z • see also

HBW

HBW may refer to:

Brinell scale, measuring indentation hardness

Handbook of the Birds of the World

Hawaiian baby woodrose (Argyreia nervosa), a perennial climbing vine with psychoactive seeds

H-B Woodlawn, a school in Arlington, Virginia, United States

HBW Balingen-Weilstetten, a German handball club

Hot bridgewire

Joshua Sanford Field, serving Hillsboro, Wisconsin, United States

Hardwood

Hardwood is wood from dicot trees. These are usually found in broad-leaved temperate and tropical forests. In temperate and boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen. Hardwood contrasts with softwood (which is from gymnosperm trees).

Hymenaea courbaril

Hymenaea courbaril (courbaril and West Indian locust) is a tree common in the Caribbean, Central America, and South America. It is a hardwood that is used for furniture, flooring, and decoration. Its hard fruit pods have edible dry pulp surrounding the seeds. Its sap, called animé, is used for incense, perfume, and varnish.

Ichalkaranji

Ichalkaranji pronunciation ) is a city in Kolhapur district in the Indian state of Maharashtra. It is governed by a municipal council.

Ichalkaranji City is known for its export of Textile goods and textile manufacturing industry. The Nearest Airport from Ichalkaranji is Pune, Maharashtra (250 km) and Belgaum, Karnataka (110 km) . Kolhapur Airport (35 km) is currently under construction. After construction, it will be the nearest airport. Ichalkaranji is in western India about 425 kilometres (264 mi) south-east of Mumbai. Ichalkaranji is slowly merging with Sangli and Miraj. Connectivity from Ichalkaranji to Sangli is very good.

Index of physics articles (B)

The index of physics articles is split into multiple pages due to its size.

To navigate by individual letter use the table of contents below.

Johan August Brinell

August Brinell (19 June 1849 – 17 November 1925) was a Swedish Metallurgical Engineer.

Brinell is noted as the creator of a method for quantifying the surface hardness of materials, now known as the Brinell hardness test. His name is also commemorated in the description of a failure mechanism of material surfaces known as Brinelling.

List of copper alloys

Copper alloys are metal alloys that have copper as their principal component. They have high resistance against corrosion. The best known traditional types are bronze, where tin is a significant addition, and brass, using zinc instead. Both these are imprecise terms, both having been commonly referred to as lattens in the past. Today the term copper alloy tends to be substituted, especially by museums.

Mohs scale of mineral hardness

The Mohs scale of mineral hardness is a qualitative ordinal scale characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material. Created in 1812 by German geologist and mineralogist Friedrich Mohs, it is one of several definitions of hardness in materials science, some of which are more quantitative. The method of comparing hardness by observing which minerals can scratch others is of great antiquity, having been mentioned by Theophrastus in his treatise On Stones, c. 300 BC, followed by Pliny the Elder in his Naturalis Historia, c. 77 AD. While greatly facilitating the identification of minerals in the field, the Mohs scale does not show how well hard materials perform in an industrial setting.

MythBusters (2014 season)

The cast of the television series MythBusters perform experiments to verify or debunk urban legends, old wives' tales, and the like. This is a list of the various myths tested on the show as well as the results of the experiments (the myth is either busted, plausible, or confirmed). The 2014 season premiered on January 4, 2014, changing to a Saturday time slot. The show resumed in July, called a "new season" by the Discovery Channel. It then moved to a Thursday time slot.

This would be the last season for Kari Byron, Tory Belleci and Grant Imahara, after it was announced the build team would not be returning for the 2015 season. Hyneman and Savage would be the sole hosts of the show from this point onwards. In December 2014, Savage would go on to address the Build Team departures, indicating that the separation was a result of failed contract negotiations between Discovery Networks and the team members.

Pencil

A pencil is an implement for writing or drawing, constructed of a narrow, solid pigment core in a protective casing that prevents the core from being broken and/or marking the user’s hand.

Pencils create marks by physical abrasion, leaving a trail of solid core material that adheres to a sheet of paper or other surface. They are distinct from pens, which dispense liquid or gel ink onto the marked surface.

Most pencil cores are made of graphite powder mixed with a clay binder. Graphite pencils (traditionally known as 'lead pencils') produce grey or black marks that are easily erased, but otherwise resistant to moisture, most chemicals, ultraviolet radiation and natural aging. Other types of pencil cores, such as those of charcoal, are mainly used for drawing and sketching. Coloured pencils are sometimes used by teachers or editors to correct submitted texts, but are typically regarded as art supplies—especially those with waxy core binders that tend to smear when erasers are applied to them. Grease pencils have a softer, crayon-like waxy core that can leave marks on smooth surfaces such as glass or porcelain.

The most common pencil casing is thin wood, usually hexagonal in section but sometimes cylindrical or triangular, permanently bonded to the core. Casings may be of other materials, such as plastic or paper. To use the pencil, the casing must be carved or peeled off to expose the working end of the core as a sharp point. Mechanical pencils have more elaborate casings which are not bonded to the core; instead, they support separate, mobile pigment cores that can be extended or retracted through the casing's tip as needed. These casings can be reloaded with new cores (usually graphite) as the previous ones are exhausted.

Softwood

Softwood is wood from gymnosperm trees such as conifers. The term is opposed to hardwood, which is the wood from angiosperm trees.

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