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101-509: Like the earlier CB750, it has a single front hydraulic disc brake , rear drum brake , electric starter, and SOHC eight-valve engine. The four-into-four exhaust pipes echoed those of the CB750. Unlike the earlier dry sump CB750, the smaller bike has a wet sump engine. Also, the primary drives were different, the CB750 having a duplex chain, while the CB500 had a "Hy-Vo" Morse chain. Reviewing

202-411: A 7075 alloy and hard anodised for a lasting finish. The outer disc ring is usually manufactured from grey iron . They can also be from steel or carbon ceramic for particular applications. These materials originated from motorsport use and are available in high-performance vehicles and aftermarket upgrades. Two-piece discs can be supplied as a fixed assembly with regular nuts, bolts, and washers or

303-440: A servo-effect . By contrast, a disc brake has no self-servo effect, and its braking force is always proportional to the pressure placed on the brake pad by the braking system via any brake servo, brake pedal, or lever. This tends to give the driver a better "feel" and helps to avoid impending lockup. Drums are also prone to "bell mouthing" and trap worn lining material within the assembly, causing various braking problems. The disc

404-464: A 10-tonne impeller) to be sand cast, as the chromium reduces cooling rate required to produce carbides through the greater thicknesses of material. Chromium also produces carbides with impressive abrasion resistance. These high-chromium alloys attribute their superior hardness to the presence of chromium carbides. The main form of these carbides are the eutectic or primary M 7 C 3 carbides, where "M" represents iron or chromium and can vary depending on

505-736: A 1956 TR3 with disc brakes to the public, but the first production cars with Girling front-disc brakes were made in September 1956. Jaguar began to offer disc brakes in February 1957 on the XK150 model, soon to follow with the Mark 1 sports saloon and in 1959 with the Mark IX large saloon. Disc brakes were most popular on sports cars when they were first introduced since these vehicles are more demanding about brake performance. Discs have now become

606-481: A Crosley HotShot with stock four-wheel disc brakes won the Index of Performance in the first race at Sebring (six hours rather than 12) on New Year's Eve in 1950. The Citroën DS was the first sustained mass production use of modern automotive disc brakes, in 1955. The car featured caliper-type front disc brakes among its many innovations. These discs were mounted inboard near the transmission and were powered by

707-402: A bike gets into a violent tank-slapper (high-speed oscillation of the front wheel) the brake pads in the calipers are forced away from the discs, so when the rider applies the brake lever, the caliper pistons push the pads towards the discs without actually making contact. The rider then brakes harder, forcing the pads onto the disc much more aggressively than standard braking. An example of this

808-431: A fixed caliper. A floating disc also avoids disc warping and reduces heat transfer to the wheel hub. Calipers have evolved from simple single-piston units to two-, four- and even six-piston items. Compared to cars, motorcycles have a higher center of mass : wheelbase ratio, so they experience more weight transfer when braking. Front brakes absorb most of the braking forces, while the rear brake serves mainly to balance

909-767: A fork brace, USD forks may be best stiffened by an oversized front axle). Bike disc brakes may range from simple, mechanical (cable) systems, to expensive and powerful, multi-piston hydraulic disc systems, commonly used on downhill racing bikes . Improved technology has seen the creation of vented discs for use on mountain bikes , similar to those on cars, introduced to help avoid heat fade on fast alpine descents. Discs are also used on road bicycles for all-weather cycling with predictable braking. By 2024, almost all road bikes are equipped with disc brakes, just like Mountain bikes. Drums are sometimes preferred as harder to damage in crowded parking, where discs are sometimes bent. Most bicycle brake discs are made of steel. Stainless steel

1010-672: A more complicated floating system where drive bobbins allow the two parts of the brake disc to expand and contract at different rates, therefore, reducing the chance a disc will warp from overheating. Key advantages of a two-piece disc are a saving in critical un-sprung weight and the dissipation of heat from the disc surface through the alloy bell (hat). Both fixed and floating options have their drawbacks and advantages. Floating discs are prone to rattle and collection of debris and are best suited to motorsport, whereas fixed are best for road use. The development of disc brakes began in England in

1111-563: A rule of mixtures. In any case, they offer hardness at the expense of toughness . Since carbide makes up a large fraction of the material, white cast iron could reasonably be classified as a cermet . White iron is too brittle for use in many structural components, but with good hardness and abrasion resistance and relatively low cost, it finds use in such applications as the wear surfaces ( impeller and volute ) of slurry pumps , shell liners and lifter bars in ball mills and autogenous grinding mills , balls and rings in coal pulverisers . It

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1212-604: A single stop. For these reasons, a heavy truck with disc brakes can stop in about 120% of the distance of a passenger car, but with drums, stopping takes about 150% of the distance. In Europe, stopping distance regulations essentially require disc brakes for heavy vehicles. In the U.S., drums are allowed and are typically preferred for their lower purchase price, despite higher total lifetime cost and more frequent service intervals. Still-larger discs are used for railroad cars , trams , and some airplanes . Passenger rail cars and light rail vehicles often use disc brakes outboard of

1313-475: A specification for the manufacture of grey iron for various applications. For normal car and light-truck applications, SAE specification J431 G3000 (superseded to G10) dictates the correct range of hardness, chemical composition, tensile strength, and other properties necessary for the intended use. Some racing cars and airplanes use brakes with carbon fiber discs and carbon fiber pads to reduce weight. Wear rates tend to be high, and braking may be poor or grabby until

1414-424: A spongy steel without the stress concentration effects that flakes of graphite would produce. The carbon percentage present is 3-4% and percentage of silicon is 1.8-2.8%.Tiny amounts of 0.02 to 0.1% magnesium , and only 0.02 to 0.04% cerium added to these alloys slow the growth of graphite precipitates by bonding to the edges of the graphite planes. Along with careful control of other elements and timing, this allows

1515-560: A torque wrench is used for final tightening. The vehicle manual will indicate the proper pattern for tightening as well as a torque rating for the bolts. Lug nuts should never be tightened in a circle. Some vehicles are sensitive to the force the bolts apply and tightening should be done with a torque wrench . Cast iron Cast iron is a class of iron – carbon alloys with a carbon content of more than 2% and silicon content around 1–3%. Its usefulness derives from its relatively low melting temperature. The alloying elements determine

1616-399: A year after it was opened. The Dee bridge disaster was caused by excessive loading at the centre of the beam by a passing train, and many similar bridges had to be demolished and rebuilt, often in wrought iron . The bridge had been badly designed, being trussed with wrought iron straps, which were wrongly thought to reinforce the structure. The centres of the beams were put into bending, with

1717-438: Is added in the ladle or in the furnace, on the order of 0.5–2.5%, to decrease chill, refine graphite, and increase fluidity. Molybdenum is added on the order of 0.3–1% to increase chill and refine the graphite and pearlite structure; it is often added in conjunction with nickel, copper, and chromium to form high strength irons. Titanium is added as a degasser and deoxidizer, but it also increases fluidity. Vanadium at 0.15–0.5%

1818-439: Is added to cast iron to stabilize cementite, increase hardness, and increase resistance to wear and heat. Zirconium at 0.1–0.3% helps to form graphite, deoxidize, and increase fluidity. In malleable iron melts, bismuth is added at 0.002–0.01% to increase how much silicon can be added. In white iron, boron is added to aid in the production of malleable iron; it also reduces the coarsening effect of bismuth. Grey cast iron

1919-420: Is characterised by its graphitic microstructure, which causes fractures of the material to have a grey appearance. It is the most commonly used cast iron and the most widely used cast material based on weight. Most cast irons have a chemical composition of 2.5–4.0% carbon, 1–3% silicon, and the remainder iron. Grey cast iron has less tensile strength and shock resistance than steel, but its compressive strength

2020-485: Is comparable to low- and medium-carbon steel. These mechanical properties are controlled by the size and shape of the graphite flakes present in the microstructure and can be characterised according to the guidelines given by the ASTM . White cast iron displays white fractured surfaces due to the presence of an iron carbide precipitate called cementite. With a lower silicon content (graphitizing agent) and faster cooling rate,

2121-453: Is difficult to cool thick castings fast enough to solidify the melt as white cast iron all the way through. However, rapid cooling can be used to solidify a shell of white cast iron, after which the remainder cools more slowly to form a core of grey cast iron. The resulting casting, called a chilled casting , has the benefits of a hard surface with a somewhat tougher interior. High-chromium white iron alloys allow massive castings (for example,

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2222-482: Is done mainly where the cost of a new disc may be lower than the cost of labor to resurface the old disc. Mechanically this is unnecessary unless the discs have reached the manufacturer's minimum recommended thickness, which would make it unsafe to use them, or vane rusting is severe (ventilated discs only). Most leading vehicle manufacturers recommend brake disc skimming (US: turning) as a solution for lateral run-out, vibration issues, and brake noises. The machining process

2323-468: Is notoriously difficult to weld . The earliest cast-iron artefacts date to the 5th century BC, and were discovered by archaeologists in what is now Jiangsu , China. Cast iron was used in ancient China to mass-produce weaponry for warfare, as well as agriculture and architecture. During the 15th century AD, cast iron became utilized for cannons and shot in Burgundy , France, and in England during

2424-433: Is one of the most common alloying elements, because it refines the pearlite and graphite structures, improves toughness, and evens out hardness differences between section thicknesses. Chromium is added in small amounts to reduce free graphite, produce chill, and because it is a powerful carbide stabilizer; nickel is often added in conjunction. A small amount of tin can be added as a substitute for 0.5% chromium. Copper

2525-439: Is performed in a brake lathe , which removes a very thin layer off the disc surface to clean off minor damage and restore uniform thickness. Machining the disc as necessary will maximize the mileage out of the current discs on the vehicle. Run-out is measured using a dial indicator on a fixed rigid base, with the tip perpendicular to the brake disc's face. It is typically measured about 1 ⁄ 2  in (12.7 mm) from

2626-414: Is preferred due to its anti-rust properties. Discs are thin, often about 2 mm. Some use a two-piece floating disc style, others use a one-piece solid metal disc. Bicycle disc brakes use either a two-piston caliper that clamps the disc from both sides or a single-piston caliper with one moving pad that contacts the disc first, and then pushes the disc against the non-moving pad. Because energy efficiency

2727-401: Is so important in bicycles, an uncommon feature of bicycle brakes is that the pads retract to eliminate residual drag when the brake is released. In contrast, most other brakes drag the pads lightly when released to minimize initial operational travel. Disc brakes are increasingly used on very large and heavy road vehicles, where previously large drum brakes were nearly universal. One reason

2828-430: Is that the disc's lack of self-assist makes brake force much more predictable, so peak brake force can be raised without more risk of braking-induced steering or jackknifing on articulated vehicles. Another is disc brakes fade less when hot, and in a heavy vehicle air and rolling drag and engine braking are small parts of total braking force, so brakes are used harder than on lighter vehicles, and drum brake fade can occur in

2929-417: Is the most important alloyant because it forces carbon out of solution. A low percentage of silicon allows carbon to remain in solution, forming iron carbide and producing white cast iron. A high percentage of silicon forces carbon out of solution, forming graphite and producing grey cast iron. Other alloying agents, manganese , chromium , molybdenum , titanium , and vanadium counteract silicon, and promote

3030-399: Is usually made of cast iron . In some cases, it may be made of composites such as reinforced carbon–carbon or ceramic matrix composites . This is connected to the wheel and the axle . To slow down the wheel, friction material in the form of brake pads , mounted on the brake caliper , is forced mechanically, hydraulically , pneumatically , or electromagnetically against both sides of

3131-592: The Arado Ar 96 . The German Tiger I heavy tank, was introduced in 1942 with a 55 cm Argus-Werke disc on each drive shaft. The American Crosley Hot Shot had four-wheel disc brakes in 1949 and 1950. However, these quickly proved troublesome and were removed. Crosley returned to drum brakes, and drum brake conversions for Hot Shots were popular. Lack of sufficient research caused reliability problems, such as sticking and corrosion, especially in regions using salt on winter roads. Crosley four-wheel disc brakes made

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3232-698: The Chirk Aqueduct and the Pontcysyllte Aqueduct , both of which remain in use following the recent restorations. The best way of using cast iron for bridge construction was by using arches , so that all the material is in compression. Cast iron, again like masonry, is very strong in compression. Wrought iron, like most other kinds of iron and indeed like most metals in general, is strong in tension, and also tough – resistant to fracturing. The relationship between wrought iron and cast iron, for structural purposes, may be thought of as analogous to

3333-527: The Congo region of the Central African forest, blacksmiths invented sophisticated furnaces capable of high temperatures over 1000 years ago. There are countless examples of welding, soldering, and cast iron created in crucibles and poured into molds. These techniques were employed for the use of composite tools and weapons with cast iron or steel blades and soft, flexible wrought iron interiors. Iron wire

3434-579: The Daimler Company used disc brakes on its Daimler Armoured Car of 1939. The disc brakes, made by the Girling company, were necessary because in that four-wheel drive (4×4) vehicle the epicyclic final drive was in the wheel hubs and therefore left no room for conventional hub-mounted drum brakes . At Germany's Argus Motoren , Hermann Klaue (1912-2001) had patented disc brakes in 1940. Argus supplied wheels fitted with disc brakes e.g. for

3535-555: The Isle of Man in the early 1970s. Bill Smith won the 1973 500 cc TT Production race (four laps) riding one, 8.2 seconds ahead of second place Stan Woods mounted on a Suzuki T500 two-stroke , twin . Disc brake A disc brake is a type of brake that uses the calipers to squeeze pairs of pads against a disc or a rotor to create friction . There are two basic types of brake pad friction mechanisms: abrasive friction and adherent friction. This action slows

3636-549: The Lincoln Continental . A four-wheel disc brake system was also introduced in 1965 on the Chevrolet Corvette Stingray. Most U.S. cars switched from front drum brakes to front disk brakes in the late 1970s and early 1980s. Lambretta introduced the first high-volume production use of a single, floating, front disc brake, enclosed in a ventilated cast alloy hub and actuated by cable, on

3737-607: The Reformation . The amounts of cast iron used for cannons 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 in Shropshire , England. Cast iron was also used in the construction of buildings . Cast iron is made from pig iron , which is the product of melting iron ore in a blast furnace . Cast iron can be made directly from

3838-541: The Studebaker Avanti was factory-equipped with front disc brakes as standard equipment. This Bendix system licensed from Dunlop was also optional on some of the other Studebaker models. Front disc brakes became standard equipment on the 1965 Rambler Marlin . The Bendix units were optional on all American Motors ' Rambler Classic and Ambassador models as well as on the Ford Thunderbird , and

3939-542: The Warring States period . This is based on an analysis of the artifact's microstructures. Because cast iron is comparatively brittle, it is not suitable for purposes where a sharp edge or flexibility is required. It is strong under compression, but not under tension. Cast iron was invented in China in the 5th century BC and poured into molds to make ploughshares and pots as well as weapons and pagodas. Although steel

4040-456: The driveshaft , near the differential , while most brakes today are located inside the wheels. An inboard location reduces the unsprung weight and eliminates a source of heat transfer to the tires. Historically, brake discs were manufactured worldwide with a concentration in Europe and America. Between 1989 and 2005, the manufacturing of brake discs migrated predominantly to China. In 1963,

4141-403: The surface tension to form the graphite into spheroidal particles rather than flakes. Due to their lower aspect ratio , the spheroids are relatively short and far from one another, and have a lower cross section vis-a-vis a propagating crack or phonon . They also have blunt boundaries, as opposed to flakes, which alleviates the stress concentration problems found in grey cast iron. In general,

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4242-652: The 13th century and other travellers subsequently noted an iron industry in the Alburz Mountains to the south of the Caspian Sea . This is close to the silk route , thus the use of cast-iron technology being derived from China is conceivable. Upon its introduction to the West in the 15th century it was used for cannon and shot . Henry VIII (reigned 1509–1547) initiated the casting of cannon in England. Soon, English iron workers using blast furnaces developed

4343-533: The 1720s and 1730s by a small number of other coke -fired blast furnaces. Application of the steam engine to power blast bellows (indirectly by pumping water to a waterwheel) in Britain, beginning in 1743 and increasing in the 1750s, was a key factor in increasing the production of cast iron, which surged in the following decades. In addition to overcoming the limitation on water power, the steam-pumped-water powered blast gave higher furnace temperatures which allowed

4444-415: The 1890s. The first caliper-type automobile disc brake was patented by Frederick William Lanchester in his Birmingham factory in 1902 and used successfully on Lanchester cars . However, the limited choice of metals in this period meant he used copper as the braking medium acting on the disc. The poor state of the roads at this time, no more than dusty, rough tracks, meant that the copper wore quickly, making

4545-551: The 1962 TV175. This was followed by the GT200 in 1964. MV Agusta was the second manufacturer to offer a front disc brake motorcycle to the public on a small scale in 1965, on their expensive 600 touring motorcycle featuring cable-operated mechanical actuation. In 1969, Honda introduced the more affordable CB750 , which had a single hydraulically actuated front disc brake (and a rear drum brake), and which sold in huge numbers. Unlike cars, disc brakes that are located within

4646-462: The 1972 show models, UK monthly magazine Motorcycle Mechanics described the CB500 as "one of the 'show stealers'. Four cylinders, in-line across the frame, four carburettors and single overhead camshaft motor, coupled to a five- speed gearbox give this 500 cc machine the performance of a 650 twin cylinder bike." Several CB500 machines were entered in the Production TT races on

4747-539: The French Venturi sports car manufacturer in the mid-1990s for example, but need to reach a very high operating temperature before becoming truly effective and so are not well suited to road use. The extreme heat generated in these systems is visible during night racing, especially on shorter tracks. It is not uncommon to see the brake discs glowing red during use. Ceramic discs are used in some high-performance cars and heavy vehicles. The first development of

4848-488: The alloy's composition. The eutectic carbides form as bundles of hollow hexagonal rods and grow perpendicular to the hexagonal basal plane. The hardness of these carbides are within the range of 1500-1800HV. Malleable iron starts as a white iron casting that is then heat treated for a day or two at about 950 °C (1,740 °F) and then cooled over a day or two. As a result, the carbon in iron carbide transforms into graphite and ferrite plus carbon. The slow process allows

4949-429: The benefit of what is called precipitation hardening (as in some steels, where much smaller cementite precipitates might inhibit [plastic deformation] by impeding the movement of dislocations through the pure iron ferrite matrix). Rather, they increase the bulk hardness of the cast iron simply by virtue of their own very high hardness and their substantial volume fraction, such that the bulk hardness can be approximated by

5050-537: The blast furnaces at Coalbrookdale. Other inventions followed, including one patented by Thomas Paine . Cast-iron bridges became commonplace as the Industrial Revolution gathered pace. Thomas Telford adopted the material for his bridge upstream at Buildwas , and then for Longdon-on-Tern Aqueduct , a canal trough aqueduct at Longdon-on-Tern on the Shrewsbury Canal . It was followed by

5151-539: The bolt holes were also cast and not drilled. Thus, because of casting's draft angle, the tension from the tie bars was placed on the hole's edge rather than being spread over the length of the hole. The replacement bridge was built in wrought iron and steel. Further bridge collapses occurred, however, culminating in the Norwood Junction rail accident of 1891. Thousands of cast-iron rail underbridges were eventually replaced by steel equivalents by 1900 owing to

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5252-480: The brake gets hot when stopping. This is acceptable as there is sufficient time for cooling, where the maximum braking energy is very predictable. Should the braking energy exceed the maximum, for example during an emergency occurring during take-off, aircraft wheels can be fitted with a fusible plug to prevent the tire bursting. This is a milestone test in aircraft development. For automotive use, disc brake discs are commonly made of grey iron . The SAE maintains

5353-634: The brake is hot. In racing and high-performance road cars, other disc materials have been employed. Reinforced carbon discs and pads inspired by aircraft braking systems such as those used on Concorde were introduced in Formula One by Brabham in conjunction with Dunlop in 1976. Carbon–carbon braking is now used in most top-level motorsport worldwide, reducing unsprung weight , giving better frictional performance and improved structural properties at high temperatures, compared to cast iron. Carbon brakes have occasionally been applied to road cars, by

5454-402: The caliper behind the slider (to reduce the angular momentum of the fork assembly). Rear disc calipers may be mounted above (e.g. BMW R1100S ) or below (e.g. Yamaha TRX850 ) the swinging arm: a low mount provides for a marginally lower center of gravity, while an upper siting keeps the caliper cleaner and better-protected from road obstacles. One problem with motorcycle disc brakes is that when

5555-522: The carbon in white cast iron precipitates out of the melt as the metastable phase cementite , Fe 3 C, rather than graphite. The cementite which precipitates from the melt forms as relatively large particles. As the iron carbide precipitates out, it withdraws carbon from the original melt, moving the mixture toward one that is closer to eutectic , and the remaining phase is the lower iron-carbon austenite (which on cooling might transform to martensite ). These eutectic carbides are much too large to provide

5656-439: The carbon to separate as spheroidal particles as the material solidifies. The properties are similar to malleable iron, but parts can be cast with larger sections. Cast iron and wrought iron can be produced unintentionally when smelting copper using iron ore as a flux. The earliest cast-iron artifacts date to the 5th century BC, and were discovered by archaeologists in what is now modern Luhe County , Jiangsu in China during

5757-507: The cars, and Crosley-based specials, popular in SCCA H-Production and H-modified racing in the 1950s. The Crosley disc was a Goodyear -Hawley design, a modern caliper "spot" type with a modern disc, derived from a design from aircraft applications. Chrysler developed a unique braking system, offered from 1949 until 1953. Instead of the disc with caliper squeezing on it, this system used twin expanding discs that rubbed against

5858-527: The casting process). The weight and power of the vehicle determine the need for ventilated discs. The "ventilated" disc design helps to dissipate the generated heat and is commonly used on the more heavily loaded front discs. Discs for motorcycles, bicycles, and many cars often have holes or slots cut through the disc. This is done for better heat dissipation , to aid surface-water dispersal, to reduce noise, to reduce mass, or purely for non-functional aesthetics. Slotted discs have shallow channels machined into

5959-402: The cost is not prohibitive. They are also found in industrial applications where the ceramic disc's lightweight and low-maintenance properties justify the cost. Composite brakes can withstand temperatures that would damage steel discs. Porsche 's Composite Ceramic Brakes (PCCB) are siliconized carbon fiber, with high-temperature capability, a 50% weight reduction over iron discs (hence reducing

6060-627: The cotton, hemp , or wool being spun. As a result, textile mills had an alarming propensity to burn down. The solution was to build them completely of non-combustible materials, and it was found convenient to provide the building with an iron frame, largely of cast iron, replacing flammable wood. The first such building was at Ditherington in Shrewsbury , Shropshire. Many other warehouses were built using cast-iron columns and beams, although faulty designs, flawed beams or overloading sometimes caused building collapses and structural failures. During

6161-612: The credit being given to the brakes' superior performance over rivals equipped with drum brakes . Mass production began with the 1949–1950 inclusion in all Crosley production, with sustained mass production starting in 1955 Citroën DS . Disc brakes offer better stopping performance than drum brakes because the disc is more readily cooled. Consequently, discs are less prone to the brake fade caused when brake components overheat. Disc brakes also recover more quickly from immersion (wet brakes are less effective than dry ones). Most drum brake designs have at least one leading shoe, which gives

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6262-599: The development of steel-framed skyscrapers. Cast iron was also used sometimes for decorative facades, especially in the United States, and the Soho district of New York has numerous examples. It was also used occasionally for complete prefabricated buildings, such as the historic Iron Building in Watervliet, New York . Another important use was in textile mills . The air in the mills contained flammable fibres from

6363-420: The disc to aid in removing dust and gas. Slotting is preferred in most racing environments to remove gas and water and deglaze brake pads. Some discs are both drilled and slotted. Slotted discs are generally not used on standard vehicles because they quickly wear down brake pads; however, removing of material is beneficial to race vehicles since it keeps the pads soft and avoids vitrification of their surfaces. On

6464-638: The disc, master cylinder , and caliper, which contain at least one cylinder and two brake pads on both sides of the rotating disc. The development of disc-type brakes began in England in the 1890s. In 1902, the Lanchester Motor Company designed brakes that looked and operated similarly to a modern disc-brake system even though the disc was thin and a cable activated the brake pad. Other designs were not practical or widely available in cars for another 60 years. Successful application began in airplanes before World War II. The German Tiger tank

6565-405: The disc. Friction causes the disc and attached wheel to slow or stop. The brake disc is the rotating part of a wheel's disc brake assembly, against which the brake pads are applied. The material is typically gray iron , a form of cast iron . The design of the discs varies. Some are solid, but others are hollowed out with fins or vanes joining the disc's two contact surfaces (usually included in

6666-520: The effects of sulfur, manganese is added, because the two form into manganese sulfide instead of iron sulfide. The manganese sulfide is lighter than the melt, so it tends to float out of the melt and into the slag . The amount of manganese required to neutralize sulfur is 1.7 × sulfur content + 0.3%. If more than this amount of manganese is added, then manganese carbide forms, which increases hardness and chilling , except in grey iron, where up to 1% of manganese increases strength and density. Nickel

6767-487: The first European cars sold to the public to have disc brakes, fitted to all four wheels. The Jaguar C-Type racing car won the 1953 24 Hours of Le Mans , the only vehicle in the race to use disc brakes, developed in the UK by Dunlop , and the first car at Le Mans ever to average over 100 mph. "Rivals' large drum brakes could match discs' ultimate stopping, but not their formidable staying power." Before this, in 1950,

6868-513: The form in which its carbon appears: white cast iron has its carbon combined into an iron carbide named cementite , which is very hard, but brittle, as it allows 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

6969-599: The friction surface, the balls would be forced up the holes forcing the discs further apart and augmenting the braking energy. This made for lighter braking pressure than with calipers, avoided brake fade, promoted cooler running, and provided one-third more friction surface than standard Chrysler twelve-inch drums. Today's owners consider the Ausco-Lambert very reliable and powerful, but admit its grabbiness and sensitivity. In 1953, 50 aluminum-bodied Austin-Healey 100S (Sebring) models, built primarily for racing, were

7070-605: The inner surface of a cast-iron brake drum, which doubled as the brake housing. The discs spread apart to create friction against the inner drum surface through the action of standard wheel cylinders . Because of the expense, the brakes were only standard on the Chrysler Crown and the Town and Country Newport in 1950. They were optional, however, on other Chryslers, priced around $ 400, at a time when an entire Crosley Hot Shot retailed for $ 935. This four-wheel disc brake system

7171-539: The lower edge in tension, where cast iron, like masonry , is very weak. Nevertheless, cast iron continued to be used in inappropriate structural ways, until the Tay Rail Bridge disaster of 1879 cast serious doubt on the use of the material. Crucial lugs for holding tie bars and struts in the Tay Bridge had been cast integral with the columns, and they failed in the early stages of the accident. In addition,

7272-681: The machine on which Tom Sheard rode to victory in the 1923 Senior TT . Successful application began on railroad streamliner passenger trains, airplanes, and tanks before and during World War II. In the US, the Budd Company introduced disc brakes on the General Pershing Zephyr for the Burlington Railroad in 1938. By the early 1950s, disc brakes were regularly applied to new passenger rolling stock. In Britain,

7373-605: The main alloying elements of cast iron. Iron alloys with lower carbon content are known as steel . 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 , cylinder blocks and gearbox cases. Some alloys are resistant to damage by oxidation . In general, cast iron

7474-466: The melt before the final form is produced by casting . Cast iron is sometimes melted in a special type of blast furnace known as a cupola , but in modern applications, it is more often melted in electric induction furnaces or electric arc furnaces. After melting is complete, the molten cast iron is poured into a holding furnace or ladle. Cast iron's properties are changed by adding various alloying elements, or alloyants . Next to carbon , silicon

7575-515: The modern ceramic brake was made by British engineers for TGV applications in 1988. The objective was to reduce weight, and the number of brakes per axle, as well as provide stable friction from high speeds and all temperatures. The result was a carbon-fiber-reinforced ceramic process which is now used in various forms for automotive, railway, and aircraft brake applications. Due to the high heat tolerance and mechanical strength of ceramic composite discs, they are often used on exotic vehicles where

7676-508: The molten pig iron or by re-melting pig iron, often along with substantial quantities of iron, steel, limestone, carbon (coke) and taking various steps to remove undesirable contaminants. Phosphorus and sulfur may be burnt out of the molten iron, but this also burns out the carbon, which must be replaced. Depending on the application, carbon and silicon content are adjusted to the desired levels, which may be anywhere from 2–3.5% and 1–3%, respectively. If desired, other elements are then added to

7777-399: The more common form in most passenger vehicles. However, many (lightweight vehicles) use drum brakes on the rear wheels to keep costs and weight down as well as to simplify the provisions for a parking brake . This can be a reasonable compromise because the front brakes perform most of the braking effort. Many early implementations for automobiles located the brakes on the inboard side of

7878-497: The motorcycle during braking. Modern sport bikes typically have twin large front discs, with a much smaller single rear disc. Bikes that are particularly fast or heavy may have vented discs. Early disc brakes (such as on the early Honda Fours and the Norton Commando ) sited the calipers on top of the disc, ahead of the fork slider. Although this gave the brake pads better cooling, it is now almost universal practice to site

7979-417: The outside diameter of the disc. The disc is spun. The difference between the minimum and maximum value on the dial is called lateral run-out. Typical hub/disc assembly run-out specifications for passenger vehicles are around 0.002 in (0.0508  mm ). Runout can be caused either by deformation of the disc itself or by runout in the underlying wheel hub face or by contamination between the disc surface and

8080-436: The piston seal has a square cross-section, also known as a square-cut seal. As the piston moves in and out, the seal drags and stretches on the piston, causing the seal to twist. The seal distorts approximately 1/10 of a millimeter. The piston is allowed to move out freely, but the slight amount of drag caused by the seal stops the piston from fully retracting to its previous position when the brakes are released, and so takes up

8181-418: The properties of malleable cast iron are more like those of mild steel . There is a limit to how large a part can be cast in malleable iron, as it is made from white cast iron. Developed in 1948, nodular or ductile cast iron has its graphite in the form of very tiny nodules with the graphite in the form of concentric layers forming the nodules. As a result, the properties of ductile cast iron are that of

8282-762: The relationship between wood and stone. Cast-iron beam bridges were used widely by the early railways, such as the Water Street Bridge in 1830 at the Manchester terminus of the Liverpool and Manchester Railway , but problems with its use became all too apparent when a new bridge carrying the Chester and Holyhead Railway across the River Dee in Chester collapsed killing five people in May 1847, less than

8383-475: The retention of carbon and the formation of those carbides. Nickel and copper increase strength and machinability, but do not change the amount of graphite formed. Carbon as graphite produces a softer iron, reduces shrinkage, lowers strength, and decreases density. Sulfur , largely a contaminant when present, forms iron sulfide , which prevents the formation of graphite and increases hardness . Sulfur makes molten cast iron viscous, which causes defects. To counter

8484-442: The road, drilled or slotted discs still have a positive effect in wet conditions because the holes or slots prevent a film of water from building up between the disc and the pads. Two-piece discs are when the center mounting part of the disc is manufactured separately from the outer friction ring. The central section used for fitment is often called the bell or hat because of its shape. It is commonly manufactured from an alloy such as

8585-412: The rotation of a shaft, such as a vehicle axle , either to reduce its rotational speed or to hold it stationary. The energy of motion is converted into heat , which must be dissipated to the environment. Hydraulically actuated disc brakes are the most commonly used mechanical device for slowing motor vehicles. The principles of a disc brake apply to almost any rotating shaft. The components include

8686-419: The slack caused by the wear of the brake pads, eliminating the need for return springs. In some rear disc calipers, the parking brake activates a mechanism inside the caliper that performs some of the same functions. Discs are usually damaged in one of four ways: scarring, cracking, warping, or excessive rusting. Service shops will sometimes respond to any disc problem by changing out the discs entirely, This

8787-531: The system impractical. In 1921, the Douglas motorcycle company introduced a form of disc brake on the front wheel of their overhead-valve sports models. Patented by the British Motorcycle & Cycle-Car Research Association, Douglas described the device as a "novel wedge brake" working on a "beveled hub flange". A Bowden cable operated the brake. Front and rear brakes of this type were fitted to

8888-501: The technique of producing cast-iron cannons, which, while heavier than the prevailing bronze cannons, were much cheaper and enabled England to arm her navy better. Cast-iron pots were made at many English blast furnaces at the time. In 1707, Abraham Darby patented a new method of making pots (and kettles) thinner and hence cheaper than those made by traditional methods. This meant that his Coalbrookdale furnaces became dominant as suppliers of pots, an activity in which they were joined in

8989-399: The thickness variation. Machining on-car with the proper equipment can also eliminate lateral run-out due to hub-face non-perpendicularity. Incorrect fitting can distort (warp) discs. The disc's retaining bolts (or the wheel/lug nuts, if the disc is sandwiched in place by the wheel) must be tightened progressively and evenly. The use of air tools to fasten lug nuts can be bad practice unless

9090-479: The underlying hub mounting surface. Determining the root cause of the indicator displacement (lateral runout) requires the disassembly of the disc from the hub. Disc face runout due to hub face runout or contamination will typically have a period of 1 minimum and 1 maximum per revolution of the brake disc. Discs can be machined to eliminate thickness variation and lateral run-out. Machining can be done in situ (on-car) or off-car (bench lathe). Both methods will eliminate

9191-566: The use of higher lime ratios, enabling the conversion from charcoal (supplies of wood for which were inadequate) to coke. The ironmasters of the Weald continued producing cast irons until the 1760s, and armament was one of the main uses of irons after the Restoration . The use of cast iron for structural purposes began in the late 1770s, when Abraham Darby III built The Iron Bridge , although short beams had already been used, such as in

9292-451: The vehicle's central hydraulic system. This model went on to sell 1.5 million units over 20 years with the same brake setup. Despite early experiments in 1902, from British Lanchester Motor Company , and in 1949 from Americans Chrysler and Crosley , the costly, trouble-prone technology was not ready for mass production. Attempts were soon withdrawn. The Jensen 541 , with four-wheel disc brakes, followed in 1956. Triumph exhibited

9393-488: The vehicle's unsprung weight), a significant reduction in dust generation, substantially extended maintenance intervals, and enhanced durability in corrosive environments. Found on some of their more expensive models, it is also an optional brake for all street Porsches at added expense. They can be recognized by the bright yellow paintwork on the aluminum six-piston calipers. The discs are internally vented much like cast-iron ones, and cross-drilled. In automotive applications,

9494-474: The wheel, bike disc brakes are in the airstream and have optimum cooling. Although cast iron discs have a porous surface that provides superior braking performance, such discs rust in the rain and become unsightly. Accordingly, motorcycle discs are usually stainless steel, drilled, slotted, or wavy to disperse rainwater. Modern motorcycle discs tend to have a floating design whereby the disc "floats" on bobbins and can move slightly, allowing better disc centering with

9595-465: The wheels, which helps ensure a free flow of cooling air. Some modern passenger rail cars, such as the Amfleet II cars , use inboard disc brakes. This reduces wear from debris and provides protection from rain and snow, which would make the discs slippery and unreliable. However, there is still plenty of cooling for reliable operation. Some airplanes have the brake mounted with very little cooling, and

9696-518: The widespread concern about cast iron under bridges on the rail network in Britain. Cast-iron columns , pioneered in mill buildings, enabled architects to build multi-storey buildings without the enormously thick walls required for masonry buildings of any height. They also opened up floor spaces in factories, and sight lines in churches and auditoriums. By the mid 19th century, cast iron columns were common in warehouse and industrial buildings, combined with wrought or cast iron beams, eventually leading to

9797-461: Was also produced. Numerous testimonies were made by early European missionaries of the Luba people pouring cast iron into molds to make hoes. These technological innovations were accomplished without the invention of the blast furnace which was the prerequisite for the deployment of such innovations in Europe and Asia. The technology of cast iron was transferred to the West from China. Al-Qazvini in

9898-417: Was built by Auto Specialties Manufacturing Company (Ausco) of St. Joseph, Michigan , under patents of inventor H.L. Lambert, and was first tested on a 1939 Plymouth . Chrysler discs were "self-energizing," in that some of the braking energy itself contributed to the braking effort. This was accomplished by small balls set into oval holes leading to the braking surface. When the disc made initial contact with

9999-467: Was fitted with discs in 1942. After the war, technological progress began in 1949, with caliper-type four-wheel disc brakes on the Crosley line and a Chrysler non-caliper type. In the 1950s, there was a demonstration of superiority at the 1953 24 Hours of Le Mans race, which required braking from high speeds several times per lap. The Jaguar racing team won, using disc brake-equipped cars, with much of

10100-410: Was more desirable, cast iron was cheaper and thus was more commonly used for implements in ancient China, while wrought iron or steel was used for weapons. The Chinese developed a method of annealing cast iron by keeping hot castings in an oxidizing atmosphere for a week or longer in order to burn off some carbon near the surface in order to keep the surface layer from being too brittle. Deep within

10201-473: Was the Michele Pirro incident at Mugello, Italy 1 June 2018. At least one manufacturer has developed a system to counter the pads being forced away. A modern development, particularly on inverted ("upside down", or "USD") forks is the radially mounted caliper. Although these are fashionable, there is no evidence that they improve braking performance or add to the fork's stiffness. (Lacking the option of

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