Dictionary of Automotive Terms Abbreviations

DICTIONARY OF AUTOMOTIVE TERMS - "Bl"

BL: Acronym for British Leyland

Black: Of parts of castings and forgings not finished by machining, the dark coating of iron-oxide retained by the surface.

Also See
Antimony black
Carbon black

Black and white checkered flag: A flag which is waved at the finishing line in races to indicate the winner.

Black body: A body which completely absorbs any heat or light radiation falling upon it. A black body maintained at a steady temperature is a full radiator at that temperature, since any black body remains in equilibrium with the radiation reaching and leaving it. Also called complete radiator

Black-body radiation: Radiation that would be radiated from an ideal Black body. The energy distribution is dependent only on the temperature and is described by Planck's radiation law.

Also See
Sefan-Boltzmann law
Wien's laws

Black-body temperature: The temperature at which a Black body would emit the same radiation as is emitted by a given radiator at a given temperature. The black-body temperature of carbon-arc crater is about 3500°C, whereas its true temperature is about 4000°C

Black book: A popular listings of the current car prices, based on age, condition, and optional equipment; published in the Kelly Black Book.

Black box

A recording device which reveals conditions just prior to a crash.

Also See
Flight recorder
A control unit. A self-contained unit of electronic circuitry; not necessarily black. It should produce a defined output for a defined input without the operator needing to know its contents. Also called brain box

Black burst: A signal without picture information but with Sync pulses, Color burst, and Black level

Black chromium plating: An electroplating deposit of a black chromium layer for decorative purposes.

Black copper: Impure metal, carrying some iron, lead, and sulfur. Produced from copper ores by blast furnace reduction.

Black crush: Tonal distortion in the picture whereby varying dark tones are all reproduced as black.

Blackening: See
Bulb blackening
Lamp blackening

Black flag: A flag which is colored black and is waved at a race. It indicates that the Driver must return to his pit for consultation. It means that the driver has violated a serious racing rule such as spilling fluid on the track or was Speeding on the pit road.

Black flag with orange circle: Black Flag With Orange Circle

As with the black flag for infractions, the black flag with orange circle means the driver must bring the car to the pits on the next lap. This flag indicates there is a serious mechanical problem with the car that can endanger the driver or others. Ignoring this black flag can bring severe penalties as it represents a dangerous situation.

Blackhawk: A vehicle brand of which the 1925-1948 models are Classic cars.

Blackheart: A form of malleable iron, in which the core contains rosettes of graphite which appear as a dark area on fracture surfaces.

Blacking: Carbonaceous material applied as a powder or wash to the internal surfaces of a mold to protect the sand and improve the finish of the casting. Prepared in a blacking mill.

Blacking a tape: Preparing a blank tape for the Insert edit by recording a black burst signal which lays down the video tracks and control track

Black liquor: A byproduct of the paper production process, alkaline spent liquor, that can be used as a source of energy. Alkaline spent liquor is removed from the digesters in the process of chemically pulping wood. After evaporation, the residual black liquor is burned as a fuel in a recovery furnace that permits the recovery of certain basic chemicals.

Blackman theory of specific heats of solids: A theory based on the dynamics of a crystal lattice of particles developed by Born and von Karman. It is more exact, but much more complicated than the Debye theory of specific heats of solids which treats the crystal as a continuous isotropic medium.

Black Orion: Trade name for precursor to carbon fiber.

Black red heat: Temperature at which hot metal is just seen to glow in subdued daylight (about 540°C)

Black sand: A mixture of sand and powdered coal forming the floor of an iron foundry.

Blacksmith hammer: Blacksmith hammer

A special hammer for hitting and shaping heated iron.

Black smoke: Incompletely burned fuel in the exhaust indicating the fuel mixture is too rich.

Black start: A power source's ability to power up from a cold shut down condition to fully operational status through a dedicated auxiliary power source that is totally independent of external systems.

Blackwall: Tires which do not have any white or red coloring.

Also See
Whitewall
Red line

Black and white flag: Black and white flag

The black and white flag is used in some series to indicate unsportsmanlike conduct. This is typically held motionless next to a pit board with the car number on it. The driver may be penalized when this flag is shown

Bladder: A hollow bag which can be inflated. In some instances, Fuel tanks will become rusty inside. A possible cure is to install a bladder. This is done by Flushing out the rust chips, applying an acid solution to remove any oil/gas residue, and Coating the inside with a plastic Compound. When done correctly, this plastic Coating does not dissolve when it comes in contact with Gasoline.

Blade

A straight narrow flat part like the end of a screwdriver or knife.
The part of a windshield wiper (Blade rubber) which contacts the windshield.
One of the vanes of a rotor or impeller.
The moving part of a knife-switch which carries the current and makes contact with the fixed jaws.

Also See
Articulated blade
Bumper blade
Bumping blade
Fan blade
Feeler blade
Fork blade

Blade activity factor: The capacity of a propeller blade for absorbing power, expressed as a non-dimensional function of the surface and by the formula where R is the diameter, and c is the blade chord at any radius r.

Blade angle: The angle between blade chord and plane of rotation at any radius. It is not constant because of the higher airspeed toward the tip, the incidence being progressively reduced to maintain optimum thrust. Change of blade angle from root to tip is called blade twist.

Blade connector: A plain metal tongue for forming electrical connections.

Bladed impeller: A rotating part of a centrifugal pump that has blades or vanes.

Blade loading: The thrust of a helicopter rotor divided by the total area of the blades.

Blade rubber: The rubber strip that fits into the arm of a windshield wiper.

Blades: See
Fork blades

Blade twist: See
Blade angle

Blank

The lacquer-coated disk ready for placing on a recording machine for making records with a stylus.
A piece of metal, shaped roughly to the required size, on which finishing processes are carried out.

Also See
Sheet metal blank

Blanket

Region of Fertile material surrounding the core in a breeder reactor in which neutrons coming from the core breed more fissile fuel, e.g., uranium-233 from thorium.
The lithium surrounding a fusion reactor core within which fusion neutrons are slowed down, heat is transferred to a primary coolant and tritium is bred from lithium.

Blank flange: A disk, or solid flange, used to blank off the end of a pipe.

Blank groove: Unmodulated groove on disk recording.

Blanking

Blocking or diabling a circuit for a required interval of time.
Suppression of the picture information while the scanning spot of a cathode ray tube returns after each line, horizontal blanking, or after each field, vertical blanking, taking place during the blanking interval.

Blanking piece: A flat piece of metal which closes off a tube. Also called a blanking plate

Blanking plate: A flat piece of metal which closes off a tube. Also called a blanking piece

Blanking plug: A rubber stopper for filling in the holes of sheetmetal such as drain holes in the floorpan.

Blast: Air under pressure, blown into a furnace.

Also See
Ocean liner blast horn
Sand blast

Blast cleaning: The removal of corrosion, dirt, paint, etc. by a blast of abrasive particles.

Also See
Abrasive blast cleaning.
Bead blasting
Sand blasting

Blaster: See
Bead blaster

Blast freezer: Low -temperature evaporator which uses a fan to force air rapidly over the evaporator surface.

Blast furnace: Vertical shaft furnace into the top of which ore mineral or scrap metal, fuel, and slag-forming rock (Flux) is charged. Air, sometimes oxygen-enriched and pre-heated, is blown through from below and products are separately tapped (slag higher and metal lower). Used to smelt iron ore, copper, lead, zinc, and other minerals.

Blast horn: See
Ocean liner blast horn

Blasting

A marked increase in amplitude distortion due to overloading the capacity of some part of a sound-reproducing system; e.g., attempt to exceed 100% depth of modulation in a radio transmitter, or break of continuity in carbon granules in a carbon transmitter.
The operation of disintegrating rock etc. by boring a hole in it, filling with gunpowder or other explosive charge, and firing it.

Also See
Bead blasting
Grit blasting
Shot blasting

Blasting fuse: Compound designed to burn at a regulated speed when closed in a tube, used to ignite detonator or explode blasting charge. Types include safety (slow) and detonating (instantaneous).

Blast main: The main blast air-pipes supplying air to a furnace

Blast pipe: Device located in the smoke-box of a steam locomotive used to improve the draft through the fire-tubes. Exhaust steam passing from the nozzle of the blast pipe reduces smoke-box pressure and induces the draft.

Blast wave: See
Shock wave

Blatthaller loudspeaker: First electrodynamically driven loudspeaker used for high-quality sound reproduction. It has a flat surface which is large compared to the wavelength of the radiated sound and it generates sound of high intensity.

Blavier's test: A method of locating a fault on an electric cable; resistance measurements are taken with the far end of the cable free, and again with it grounded.

Blaze: Temporary survey mark, such as slash on tree trunk, to guide prospector or explorer

BLC: Acronym for Backlight compensation

Bleed

To remove air bubbles from hydraulic lines and Components of a system.
Also See
Air bleed
Air bleed screw
Idle air bleed screw
Compensating jet
To reduce the air pressure in tires that have been run, warmed up, and thus increased from their starting pressure -- an action which should be avoided.

Bleed down: The collapse of a hydraulic lifter as oil drains out.

Bleeder: The valve or screw used to vent the air out of a liquid-filled system.

Also See
Brake bleeder
Pressure bleeder

Bleeder jar: A glass or transparent plastic container used to detect the escape of air while bleeding brakes

Bleeder nipple: See
Bleeder screw

Bleeder resistor: Resistor placed across secondary of transformer to regulate its response curve, esp. when the transformer is not loaded with a proper terminating resistance. One placed in a power supply or rectifier circuit to control its regulation.

Bleeder screw

A hollow screw used to open a bleeder valve to allow fluid and air bubbles from a system like the Brake system during a bleeding process.
A small hollow screw or valve found at drum brake wheel cylinders, in disc brake calipers, and adjacent to the outlet ports of some master cylinders. It is opened to release pressure and bleed air and fluid from the hydraulic system after reconditioning or in the event air has gotten into the system.

Also See
Idle air bleed screw

Bleeder tank: A container that stores brake fluid under pressure. When connected to the master cylinder, the fluid is forced through the system and facilitates bleeding.

Bleeder tubes: Short curved pieces of tubing used in the bleeding of master cylinders.

Bleeder valve

A valve on a wheel cylinder, caliper, or other hydraulic component that is opened to purge or release air from the hydraulic system.
The device which vents air from the Brake system.

Bleeder wrench: A tool used to open bleeder valves

Bleeding

The tapping of air from a gas turbine compressor to prevent Surging.
The tapping of air from a gas turbine compressor to feed some other equipment, e.g., cabin pressurization or a de-icing system.
A paint defect in which a constituent in an underlying surface discolors subsequent coatings, prevented by applying a barrier coating.
A method of improving the thermal efficiency of a steam plant by withdrawing a small part of the steam from the higher-pressure stages of a turbine to heat the feed-water.
Removing undesirable entrapped air from a hydraulic (e.g., braking) system.
Diffusion of dye from an photographic image.
In fibers, yarns or fabrics of two or more colors, the running of the darker colors, and consequent staining of the lighter colors; during finishing, washing, or solvent cleaning.
The action of venting air from a liquid-filled ( Hydraulic) system.
Reducing the air pressure in tires that have been run, warmed up, and thus increased from their starting pressure -- an action which should be avoided.
Slowly reducing the pressure of liquid or gas from a system or cylinder by slightly opening a valve
The separation of components of a dried adhesive, coating, or sealer film, resulting in an oil-like stain on the surfaces to be bonded, or on finishes
A lower (older or previous) color coming through a fresh Coat of paint.

Also See
Brake bleeding

Bleeding a system: Remove air bubbles from a Brake system, a Fuel injection system, or a Cooling system so that they won't impede the flow of liquid through that system.

Bleeding sequence: The order of bleeding brake system components

Bleeding the brakes: This refers to the removal of air from the Hydraulic system, bleeder screws are loosened at each Wheel cylinder, (one at a time) and Brake fluid is forced from the Master cylinder through the lines until all air is expelled.

Bleeds: See
Anti-siphon bleeds

Bleed screw: A screw used to release the air from a system like the Brake system.

Also See
Idle air bleed screw
Air bleed screw

Bleed valve

A valve with small opening inside which permits a minimum fluid flow when valve is closed.
The device which vents air from the Brake system.

Blem: An abbreviation for Blemish tire.

Blemish: A tire with a slight imperfection in appearance that will not affect tire life or safety. Also called a blem.

Blender: A device for mixing two fuel oils to achieve a less viscous and more uniform fuel.

Blending: Mixing of two compatible fuels having different properties in order to produce an intermediate fuel

Blending components: See
Motor gasoline blending components.

Blending plant: A facility that has no refining capability but is either capable of producing finished motor gasoline through mechanical blending or blends oxygenates with motor gasoline.

BLEU: Acronym for Blind Landing Experimental Unit operated by the Royal Aircraft Establishment which developed a fully automatic blind landing system.

Also See
Autothrottle
Flight director

B-licence: Commercial pilot's licence

Blimp: Colloquial term for a non-rigid Airship

Blind: See
Car blind

Blind flying: The flying of an aircraft by a pilot who, because of darkness or poor visibility, must rely on the indication of instrument.

Also See
Ground-controlled approach
Instrument landing system

Blind flying instruments: A group of instruments, often on an individual central panel, essential for Blind flying. Commonly airspeed indicator, altimeter, vertical speed, turn-and-slip, artificial horizon, and directional gyro.

Also See
Basic six
Basic T

Blinding

Sprinkling small chippings of stone over a tar-dressed road surface.
Placing a thin layer of concrete over a foundation area before the structural concrete is placed.

Blind landing: The landing of an aircraft by a pilot who, because of darkness or poor visibility, must rely on the indication of instruments.

Also See
Ground-controlled approach
Instrument landing system

Blind quarter: An unusually wide C-pillar enclosing the rear seat area.

Blind rivet: A type of rivet which can be clinched as well as placed by access to one side only of a structure. Usually based on a tubular or semitubular rivet design such as a Pop rivet, Chobert rivet, and Explosive rivet.

Blind spot: An area not visible from the driver's seat. It is usually the area behind the rear quarter and not visible to the driver either through the windshield, side windows, or mirrors. When approaching another vehicle in a lane beside you, avoid being in its blind spot. Also do a shoulder check before switching lanes to check for vehicles in the blind spot. Also see Front-end blind spot.

Blinkie: Blinkie

A red taillight on a bicycle which has a switch which turns it to a steady light or a flashing (blinking) light

Blinking: Modification of a loran transmission, so that a fluctuation in display indicates incorrect operation.

Blip: Spot on cathode-ray tube screen indicating radar function.

Blister

A bubble on a paint surface.
A localized bubble on the surface of a tire, normally caused by a separation between plies or between surface rubber and a ply.
A raised area on the surface of solid metal produced by the emanation of gas from within the metal while it is hot and plastic.

Blister copper: An intermediate product in the manufacture of copper. It is produced in a converter, contains 98.4-99.5% copper, and is subsequently refined to give commercial varieties, e.g., tough pitch, deoxidized copper.

Blistering: The formation of bubbles on the paint surface.

Blister pack: Transparent, thin sheet of plastic thermoformed to cover product for display purposes. Also called bubble pack.

Blister steel: Wrought-iron bars impregnated with carbon by heating in charcoal. Before 1740 this was the only steel available. Obsolete.

BLM

Acronym for Block Learn Multiplier--a term replaced with Long Term Fuel Trim
Acronym for the Bureau of Land Management

BLMC: Acronym for British Leyland Motor Corporation

Bloch band: See
Band theory of solids

Bloch function: The solutions of the Schrödinger equation for electrons in a crystalline solid which have the same periodicity as the periodic potential function under whose influence the electrons move.

Also See
Band theory of solids

Bloch wall: The wall of a Magnetic domain

Block: Click image to supersize
Engine Block

That part of the engine containing the Cylinders.
Also See
Angle block
Bearing block
Big-block
Block heater
Brake block
Brake pad
Breech block
Cylinder block
Die
EN-block
En block
Engine block heater
Engine block Hollowing block
Hydraulic control block
Keel blocks Long block
Long block engine
Monoblock
Rubbing block
Sanding block
Short block
Tread block
Valve block

Block brake: A vehicle brake in which a block of cast-iron is forced against the rim of the revolving wheel, either by hand-power, electromagnetic mechanism, or fluid-pressure acting on a piston.

Also See
Air brake
Electromagnetic brake

Block clutch: A Friction clutch in which friction blocks or shoes are forced inward into the grooved rim of the driving member, or expanded into contact with the internal surface of a drum.

Block coefficient: The ratio of the underwater volume of a ship to the volume of a rectangular block with the same effective lengths, draft and beam.

Block deck: The cylinder head gasket surface.

Blocked impedance: The impedance of the input of a Transducer when the output load is infinite, e.g., when the mechanical system, as in a loudspeaker, is prevented from moving.

Block engine: See
Long block engine
Short block engine

Blocker ring: Blocker ring

A component in a sychromesh system which contains the internal cone. It separates the collar and gear, and prevents the dogs from engaging until all parts are precisely sychronized. When the shift fork engages the cones, the blocker ring shifts slightly so that its dogs prevent the sleeve from engaging the gear wheel. The shift lever resists any effort to push it into gear. When the speed of all three parts are sychronized, the blocker ring shifts again, allowing the sleeve to move forward and engage the aligned dogs on the blocker ring and gear.

Block heater: A devices which, during very cold weather, keeps the engine warm when the vehicle is not being used -- thus making cold starts easier. The free end is plugged into 110 volt AC wall socket. It is especially important for starting Diesel engines at very low temperatures.

Also See
Cylinder block heater
Engine block heater

Blocking

Cut-off of anode current in a valve because of the application of a high negative voltage to the grid; used in Gating or Blanking.
Tendency of polymer film to adhere to itself, a problem in manufacture. Inhibited with surface coating of an anti-blocking agent.

Blocking capacitor: One in signal path to prevent DC continuity. Also called buffer capacitor

Blocking ring: See
Balk ring

Blocks: See
Keel blocks

Block sanding: The process of using a wooden block wrapped in sandpaper to sand the material.

Block section: The length of track in a railway system that is limited by stop signals.

Block system: The system of controlling the movements of trains by signals and by independent communication between block posts, where the instruments indicating the position of trains, condition of the block sections, and controlling levers for signals, points, etc. are situated. It is absolute if one train alone is permitted within a block section, and permissive if trains are allowed to follow into a block section already occupied by a train.

Block time: The time elapsed from the moment an aircraft starts to leave its loading point to the moment when it comes to rest. It is an important factor in airline organization and scheduling. Also called chock-to-chock, buoy-to-buoy (seaplanes), flight time.

Blondel-Rey law: A law used to assess the apparent point brilliance B of a flashing light B=B₀[f / (a+f)], where B₀ is the point brilliance during the flash, f is the duration of the flash in seconds and a is constant of value about 0.2 s, and B is near the threshold value for white light. The law holds for flashing frequencies less than 5 Hz.

Blondin: See
Cable-way

Blood alcohol content: The amount of alcohol in the bloodstream as a result of drinking liquor.

Blood alcohol level: The amount of alcohol in the bloodstream as a result of drinking liquor.

Blood red heat: Dark red glow from heated metal, in temperature range 550°C - 630°C

Bloom

A surface film on rubber, caused by the migration to the surface of sulfur, wax, or other unreacted ingredients of the compound. It may be protective to the tire and detrimental only if appearance is a major factor.
Semifinished metal, rectangular in cross-section and for steel not more than twice as long as it is thick. Compare Billet
Surface film on glass, the thin dielectric layers vacuum deposited on a lens to alter its reflectance properties, hence blooming, see Coated lens
The film of sulfites and sulfates formed on glass during the annealing process.
The film on glass caused by weathering. Obsolete.

Blooming

A formation of an undesired thin surface film or a milky white haze or mist on paintwork. It is caused when paint is applied during humid, cold conditions as moisture is trapped in the wet film.
Treatment of the glass-air surfaces of a lens with a deposit of magnesium fluoride or other substance, which reduces internal reflection and increase light transmission.
Spread of spot on cathode-ray tube phosphor due to excessive beam current.
Coating of dielectric surfaces to reduce reflection of electromagnetic waves.

Blooming mills: The rolling mills used in reducing steel ingots to blooms. Called cogging mills in the UK, and not always distinguished from billet (slab) mills.

Blow

To become defective either by leaking or burning through.
In a Bessemer converter, passage of air through molten charge.

Also See
Arc blow
Striking blow

Blow back

Because of a sticky valve or the intake valve closing late, some of the air-fuel mixture is blown back through the carburetor.
The return, at low speeds, of some of the induced mixture through the carburetor of a gasoline engine; due to the late closing of the intake valve during compression, or by worn or sticking valves.

Blowby: The Mixture of fuel-air which is lost past the Piston rings and causes fumes that form acid and Sludge in the Crankcase and smoking from the oil filer hole. Generally there is a loss of engine power. Most are removed through the PCV system.

Blow-by: The Mixture of fuel-air which is lost past the Piston rings and causes fumes that form acid and Sludge in the Crankcase and smoking from the oil filer hole. Generally there is a loss of engine power. Most are removed through the PCV system.

Blowdown

The escape of gases between the opening of the exhaust valve and the piston reaching bottom dead center, or in a two-stroke engine between exhaust port opening and transfer port opening.
The difference between the opening and closing pressures of a relief/safety valve.

Blowdown period: In a two-stroke engine, it is the time between the exhaust port opening and the transfer port opening which should be sufficiently long enough to allow time for the cylinder pressure to drop below the crankcase pressure, so that the exhaust gases can be expelled more easily.

Blower

Also called a Supercharger or Turbocharger. This is a Pump which forces air into the Cylinders at higher than Atmospheric pressure. The increased pressure forces more air into the Cylinders than what would be drawn in normally. In this way the engine can burn more fuel and thus produce more power. There are two main types of blowers the Turbocharger, which uses some of the waste heat energy in the Exhaust gases to drive a Compressor and pump the air; and the belt-driven or shaft-driven supercharger which uses engine power to pump air.
A fan for an interior heating and ventilating system or even for an air-cooled engine.
A fan used to force air and/or gas under pressure.
A ring-shaped perforated pipe, encircling the top of the Blast pipe in the smoke-box, to which steam is supplied while a steam engine is standing, the jets providing sufficient draft to keep the fire going.

Also See
Heater blower

Blower fan: An electric motor-driven fan which forces air through the evaporator and duct assembly, then forces the cooled air out of the duct work and circulates it through the vehicle passenger compartment.

Blower motor resistor: A device which regulates fan speed.

Blow gun: Blow gun

A paint spray gun with a wide nozzle which is fed by air pressure. It is used to blow out crevices in material that is otherwise hard to reach.

Blowhole: A gas-filled cavity in a solid metal. Usually formed by the trapping of bubbles of gas evolved during solidification (see Gas evolution), but may also be caused by steam generated at the mold surface, air entrapped by the incoming metal, or gas given off by inflammable mold dressing.

Blowing current: The current (DC or rms) which will cause a fuse link to melt.

Blowing engine: The combined steam-engine or gas-engine and large reciprocating air-blower for supplying air to a blast furnace.

Blowing-out: The operation of stopping down a blast furnace.

Blowlamp: A British term for Blow torch

Blow molding: Two-stage route for making hollow products, e.g., bottles, surfboards (when filled with foam). Extruded Parison is dropped into the split, female-only tool, and blown to shape by air pressure.

Blown

An engine equipped with a Turbocharger or Supercharger.

Also See
Boost
An engine which is ruined. Usually the Piston is Seized.

Also See
Blown head gasket.

Blown casting: Casting spoiled by porosity

Blown engine: An engine which has suffered some internal damage and will need extensive repair or replacement.

Blown film: Polymer process where molten low-density polyethylene extrudate is blown by air pressure to make thin film for packaging, etc.

Also See
Extrusion

Blown flap: A Flap, the efficiency of which is improved by blowing air or other gas over its upper surface to maintain attached airflow even at high angles of deflection.

Blown head gasket: A Gasket that has a break between the opening for the Cylinder and an opening for the Coolant. The Coolant will leak into the Combustion chamber. This condition can be diagnosed by a loss in Coolant and white smoke out the Exhaust.

Blowoff valve: Blowoff Valve

A one-way valve that opens to the atmosphere above a certain set pressure to relieve excessive internal pressure buildup; often used with a Turbocharger installation to limit Boost pressure to the engine. Also called Pressure-relief valve.

Also See
Wastegate

Blow-off valve: See
Blowoff valve

Blow out: To clean a dirty or blocked pipe by blowing compressed air through it.

Blowout: A sudden rupturing of tire body, causing complete loss of air pressure which flattens the tire.

Blow-out: A sudden rupturing of tire body, causing complete loss of air pressure which flattens the tire.

Blowout coil: See
Magnetic blowout

Blowout magnet: A permanent or electromagnet used to extinguish more rapidly the arc (in a switch, etc.) caused by breaking an electric circuit.

Blow-over: A respray of doubtful quality, often poorly prepared and carelessly masked.

Blow pin: Device through which air is blown in final stage of Blow molding. Usually ascends into base of descending Parison

Blowpipe: Another term applied to the oxyacetylene torch.

Blow through: A turbocharger system in which the turbocharger blows air through the carburetor(s) or fuel injector(s), i.e., the air and fuel mixing occurs downstream from the turbocharger.

Blow torch: Blow Torch

A tool which is attached to a bottle of flammable gas. The gas is ignited to give an intense flame for brazing and soldering. The British term is blowlamp

Bluebird: Trucker slang for a Martin Truck company's truck as in "Can I get a smokey report there Bluebird."

Blue billy: The residue left after burning off the sulfur from iron sulfide ores.

Blue book: A listing of the Current prices for used cars, based on age, condition, and Optional equipment; published in the Kelly Blue Book. Available at banks, loan offices, libraries, and insurance companies.

Blue brittleness: Embrittlement of medium and high carbon steels during tempering in the range of 205°C - 315°C, so named because the surface of the steel becomes coated with blue colored oxidation film.

Blue flag: Blue flag

The blue or passing flag has different meanings depending on how it is held and whether it is used during practice, qualifying or racing. Generally when it is held motionless it is an indication to a driver that there is a faster car following closely behind, but not yet close enough for a pass. A waving flag generally indicates that the driver is about to be overtaken and should take care to permit the following vehicle a safe pass. Some drivers resist moving over for an over-taking car when they feel they are racing for position. Controversy can follow the use of the passing flag. Some tracks use a blue flag with a diagonal yellow stripe.

Blueing

The blue color that appears on chrome pipes when subject to intense heat. In some cases, it can be removed; but most often it is permanent.
The production of a blue oxide film on polished steel by heating in contact with saltpeter or wood ash, either to form a protective coating, or incidental to annealing

Blueing salts: Caustic solution of sodium nitrate, used hot to produce a blue oxide film on the surface of steel.

Blue metal: Condensed metallic fume resulting from distillation of zinc from its ore concentrates. Blue tint is due to slight surface-oxidation of the fine particles.

Blueprinting: Dismantling engine and reassembling it to exact Specifications and Tolerances. This process may help to improve engine performance, smoothness, and reliability. Sometimes called Balancing.

Blue smoke: The color of the exhaust which indicates that oil is escaping into the combustion chamber and being burned. It is probably due to worn rings, valve seals, etc.

Blunt start: End of a threaded screw which is rounded or coned to facilitate insertion.

Blushing: The formation of a whitish or misty appearance on the Finish color of the paint surface.