Dictionary of Automotive Terms Abbreviations

DICTIONARY OF AUTOMOTIVE TERMS - "Ha"

H

A letter rating for tires to indicate that they are theoretically rated for Speeds up to 210 kph (130 mph), as in P185HR13. The next higher rating is V and the one lower rating is T.
Système International (SI) symbol for Henry
Symbol for Hydrogen

H₂O: Acronym for Water

Habits: See
Driving habits

HAC: Acronym for High Altitude Compensator

Hackney Carriage: Black taxis in London.

Hacksaw: Hacksaw

A tool for cutting metal, with a narrow blade attached to a frame

HAI

Acronym for Heated air inlet system
Acronym for hot air intake

Hair: See
Helmet hair

Hairline crack: A tiny stress crack which forms due to strains in the material or extreme temperature differences; as opposed to crazing, a single crack of this type will often occur alone

Hair pin: Hair pin

A roadway with several sharp turns usually on an hill.

Hair pin cotter: Hair pin cotter

A securing device shaped somewhat like a U in which the legs have a series of waves or bends. Insert one leg into the hole of a rod so that the bent leg will encircle the rod.
Also See
Hitch pin clip where one leg is straight

Hairpin valve spring: A valve spring formed from a wire or metal strip bent to form two levers emanating from a half-loop or coil; used on some classic cars and motorcycles

HAIS: Acronym for Heated Air Intake System (Chrysler)

Half: See
Crankcase half

Half dog point: The same as a dog point but half as long; used on short screws for the same purposes as the dog point, but in a shallower hole or slot.

Half dog point socket set screw: A headless socket set screw threaded the entire length. It has a hexagonal drive at one end and a protruding tip with a flat surface at the other end.

Half-life: See
Biological Half-life

Half link: Half link

Every Chain has Rollers which are connected by side plates or Keepers. When counting the number of links in a length of Chain, it is easiest to count the number of side plates on one side of the Chain and multiplying the number by two. When a Chain needs to be an odd number, a half link is included. The term half link is a misnomer. It should be called a single link. The side plate on a half link is not flat but has a step down shape. For this reason, it is called an offset link.

Half moon key: See
Half-moon key.

Half-moon key: Half-moon key

A driving key serving the same purpose as the regular key but it is shaped somewhat like a half circle. Also called a Woodruff key.

Half-moon slip joint pliers: A multiple-slip joint pliers with groove joint

Half-round body file: A body file with domed file surface for working reverse-crowned panels

Half-round file: A special file that's flat on one side and convex on the other

Half shaft: A rotating shaft that transmits power from the final drive unit to one side of the drive wheels, but usually refers to the two shafts that connect the road wheels to the final drive with Independent rear suspension or Front-wheel drive as opposed to the axle shafts of a live rear axle. Also called an Axleshaft

Half step gearing: See
Half-step gearing.

Half-step gearing: A Gearing system of a Bicycle in which a shift between Chainrings in a double chainring set is equivalent to half a gear step on the Freewheel.

Halftrack: Halftrack

Vehicle with caterpillar tracks over the rear wheels to provide motive power but steered by normal front wheels

Half wave rectifier: See
Rectifier.

Half-wave rectifier: See
Rectifier.

Halide Lamp: See
Metal Halide Lamp

Halide refrigerants: Family of refrigerants containing halogen chemicals.

Halide torch: Type of torch used to safely detect halogen refrigerant leaks in system.

Hall effect: In electrical conductors where electric current flows perpendicular to a magnetic field, a so-called Hall voltage is produced perpendicular to the direction of current flow and to the magnetic field
Also see
Quantum Hall Effect

Hall-effect ignition system: Transistorized ignition with Hall generator

Hall-effect sensor: A Hall generator

Hall-effect switch: A Hall vane switch

Hall element: A pulse generator that makes use of the Hall effect and consists of a rotor with vanes, a conductive element with a permanent magnet and the Hall IC. Also called Hall generator. When the air gap is unobstructed, a Hall voltage is generated; when a vane stands in the air gap, the magnetic flux cannot reach the Hall IC. Hall generators used as ignition pulse generators have as many vanes and Hall windows as the engine has cylinders, dwell being determined by the width of the vanes. Hall generators used in electronic-map ignition systems to provide the engine starting signal have only one Hall window

Hall generator: A pulse generator that makes use of the Hall effect and consists of a rotor with vanes, a conductive element with a permanent magnet and the Hall IC. Also called Hall element.

Also See
Transistorized ignition with Hall generator

Hall IC: A solid state device with the actual Hall generator and integrated circuits for voltage amplification and potential reversal, producing the pulses for the control unit

Hall module: A Hall IC

Hall sensor: A Hall generator.

Also See
Transistorized coil ignition with Hall sensor

Hall vane switch: A switch that makes use of the Hall effect. When the air gap is free, a magnetic field acts on the Hall IC and the Hall voltage reaches its maximum (high). When a rotor vane obstructs the air gap, shielding the Hall IC from the magnetic flux, the Hall voltage reaches its minimum (low). The signal produced is a square wave

Hall voltage: See
Hall effect

Halogen: One of the chemical elements fluorine, chlorine, bromine, iodine, or astatine.

Also See
Quartz halogen bulb

Halogenated substances: A volatile compound containing halogens, such as chlorine, fluorine or bromine.

Halogen bulb: A bulb containing a trace of a halogen, such as iodine. A halogen bulb gives off a brighter light.

Also See
Quartz halogen bulb

Halogen headlamps: Tungsten-halogen bulb used in sealed beam unit or as separate bulb in composite headlamp

Halogen headlight: High intensity reflector with inner halogen bulb, precision lens, and 3-prong attachment. Don't touch the glass of a halogen bulb with your fingers. The oil left on the glass will cause the glass to break or reduce the life of the bulb. If the glass is accidentally touched, it may be cleaned with methylated spirits or rubbing alcohol on a soft cloth

Halogen lamp: A type of Incandescent lamp that lasts much longer and is more efficient than the common incandescent lamp. The lamp uses a halogen gas, usually iodine or bromine, that causes the evaporating tungsten to be redeposited on the filament, thus prolonging its life.

Halogens: Substance containing fluorine, chlorine, bromine, and iodine.

Hamlin switch: A suspended-mass-type sensor used in new air bag systems; avoids the ecological problems associated with the earlier mercury-type switches

Hammer

To hit with a hammer.
To ride hard and fast.
Someone who rides hard and fast.
Trucker slang for the accelerator pedal as in "When we get past this parking lot we can really hit the hammer."
A hand tool with a head (usually metal) and a handle. It is used to force one item against or through another. Several types of hammers are available

Also See
Air hammer
Ball-pane Hammer
Ball peen hammer
Ball pien hammer
Blacksmith hammer
Body hammer
Boilermakers Hammer
Brass hammer
Bricklayer hammer
Bumping hammer
Chipping hammer
Claw hammer
Club hammer
Copper-faced hammer
Curved pein and finishing hammer
Fender bumping hammer
Finish hammer
Grooving hammer
Machinists' hammer
Nail hammer
Nylon hammer
Panel hammer
Peen hammer
Pein hammer
Pick and finishing hammer
Pick hammer
Planishing hammer
Prospector's pick
Reverse curve panel hammer
Ripping hammer
Riveting hammer
Rotary hammer
Rubber mallet
Shingler's hammer
Shrinking hammer
Sledge hammer
Slide hammer
Soft face hammer
Tack hammer
Tile setter hammer
Tinner's hammer
Two-way hammer
Water Hammer
Welding hammer
Wide-nose peen hammer
Wing bumping hammer
Wood mallet

Hammer down: Trucker slang for driving fast as in "We got a southbound smokey with the hammer down".

Hammer drill: Electric hand drill that hammers as well as rotates

Hammerform: A shaped wooden block used in panel beating, on which a desired form is produced by hammering

Hammer welding: Metalworking technique that includes gas welding, preferably without the use of filler rod, followed by hammer and Dolly work on the welded joint to smooth out any remaining imperfections

Hand: See
Left hand gear lever
Left hand monkey wrench
Left hand thread
Right hand thread
Right hand turn signal
Third hand

Handbook: A manual which gives instructions or information.

Also See
Owner's handbook
Owner's manual

Handbrake: A brake operated by a hand lever. It may also refer to the Parking brake.

Handbrake turn: 180° turn achieved by applying the handbrake (acting on the rear wheels) hard when the vehicle is starting to turn

Handbrake warning light: A light on the instrument panel that illuminates when the handbrake is applied; on most new cars it has been superseded by a multifunction brake warning light

Hand controls: An auxiliary set of components to allow disabled people to operate a vehicle.

Hand Crafted: Something that is built by hand rather than in an assembly line (i.e., mass produced).

Hand crank: Before Cadillac invented and first produced electric Starters, engines were started by means of a handle which was inserted into the front of the engine and rotated manually. After 1930 it became obsolete.

Hand cycle: Hand cycle

A human powered cycle that is propelled by rotating the crank with your hands rather than your feet. Usually there is one wheel up front and two (often smaller) in the back. It is designed for people who are unable to use their legs.

Hand drill: Hand drill

A power-driven device for boring holes or (with the correct attachment) removing or securing screws and bolts

Handed: Something that is made for a specific side of a unit. For example, left hand arm rests are not interchangeable with right hand arm rests.

Hand file: A flat File for shaping metal, with a rectangular cross section, constant blade width and one smooth edge

Hand gear: See
Left hand gear lever

Hand gear lever: See
Left hand gear lever

Hand lapped valves: A process of grinding valves by hand so that there is a perfect match between the valve and its seat.

Handle

The reaction of a vehicle under a particular circumstance, especially regarding cornering, roadholding, and maneuvering.
To deal with or to cope with (e.g., "the tires can handle 50 psi" means the tires can withstand pressure up to 50 psi).
A CB user's code name.

Also See
Boot handle
Brake Handle
Door handle
Drive handle
File handle
Flexible drive handle
Grab handle
Offset handle
Pull-out door handle
Ratchet handle
Spinner handle
Starting handle
Trunk handle

Handlebar: A steering device found on Bicycles and Motorcycles. Grips, brake levers, and shifters, etc. are attached to the handlebar.
Also see
Bullhorn handlebar

Handlebar bag: Handlebar bag

A container, usually leather and nylon, which mounts on the front of a bicycle's handlebars.

Handlebar riser: A bracket which lifts the base of the handlebar up higher.

Handler: See
Air Handler

Handling: The relative ability of a vehicle to negotiate curves and respond to road conditions. It is a factor of the weight of the vehicle, the suspension, tires, air flow, etc.

Also See
Neutral handling
Performance handling system

Handling system: See
Performance handling system

Hands: See
Glad hands

Hands-free: A car cell phone that allows the driver to dial and talk on the phone without handling the phone.

Handshaker: A colloquial term for a passenger car with a manual transmission

Hand shield: An eye and face protector held in the hand. It enables a person to look directly at the electric arc through a special lens without being harmed.

Hand thread: See
Left hand thread
Right hand thread

Hand turn: See
Right hand turn signal

Hand turn signal: See
Right hand turn signal

Hang a left: To make a left-turn

Hang a right: To make a right-hand turn

Hang a U-ey: To make a U-turn

Hanger

A flexible ring or strap to hold a pipe, e.g., an exhaust pipe.
A mounting bracket, e.g., a Spring hanger for a Leaf spring.
A component of sighting point gauges, used to install the gauge at the vehicle chassis.
Device attached to walls or other structure for support of pipe lines.

Also See
Ape Hangers
Bridge Hanger
Derailleur Hanger
Dropout hanger
Replaceable Derailleur Hanger
Spring Hanger

Hanger Bolt: Hanger bolt

A fastener where one end is gimlet pointed and has a wood screw thread. The other end consists of a coarse machine screw thread. The center section is unthreaded.

Hangover: A modification of custom cars with separate chassis, e.g., pick-ups, which raises the floorpan and lowers the body, to give the impression that the body has been pulled down over the chassis right down to street level

Hard aground: A ship which has gone aground and is not able to move under her own power.

Hard anodic coating: Hard, wear-resistant, oxide layer produced in an anodic oxidation process

Hard anodizing: A special type of anodizing adapted to the production of thick, hard, abrasion-resistant films

Hardboard: A board-like building material made of compressed wood chip fibers and sawdust

Hard chromium plating: An electrolytic deposition of a hard, wear-resistant, chromium layer

Hard code: A type of trouble code that causes the ECU to disengage the ABS and not re-engage it until the problem is repaired

Hard-dry: The condition of paint when it is hard enough to polish

Harden

The action of turning from a liquid to a solid.
To set or to cure.
The action of making the surface a metal tougher.

Also See
Case harden.

Hardenability: In a ferrous alloy, the property that determines the depth and distribution of hardness induced by quenching.

Hardened: See
Case-hardened
Chrome-hardened
Strain hardened
Work hardened

Hardened pushrods: Specially treated pushrods designed for use with pushrod-guided rocker arms

Hardener: Chemical added to plastic filler to induce hardening as used in auto body repair.

Hardening

The process of paint, epoxy, or glue becoming hard. The drying or hardening of paint film goes through several stages. The first stage is called dust-free; at this stage, the paint has hardened sufficiently to prevent dust from becoming embedded in the paint film. The second stage is called touch-dry; at this point, the paint film can actually be touched with light finger pressure. The third and final stage is referred to as hard-dry; at this point, the paint film is hard enough to polish.
A method of heat treating metals by heating to a temperature within, or above, the critical range, holding at that temperature for a given time, and then cooling rapidly, usually by quenching in oil or water.

Also See
Age-hardening
Flame hardening
Induction Hardening

Hardening media: A liquid into which steel is immersed in order to harden the steel. Usually involves cold water, brine, oil, and special polymers.

Hardness

The toughness of the surface of a metal. Normally stated in terms of Rockwell or Brinell scale of measurement, hardness shows resistance of a fastener to rough marks and abrasions, can indicate yield strength and brittleness, and has a direct relationship to tensile strength in alloy steel fasteners. However, for stainless, brass, and silicon bronze, the correlation between hardness and tensile or yield is tenuous with no definite relationship. Case-hardening uses surface heat treatment on ferrous material to cause a harder outside surface than the center. Through-hardening hardens the entire fastener. Bright hardening calls for heat treatment without oxygen, so no oxides are formed on the material surface.
Resistance to plastic deformation by indentation, penetration, scratching or bending.

Also See
Abrasion hardness
Brinell hardness
Indentation hardness
Rockwell hardness
Shore hardness
Work Hardness

Hard pedal: A loss in braking efficiency so that an excessive amount of pressure is need to actuate brakes

Hard rubber: See
Ebonite

Hard-sided caravan: A British term for a trailer with foldable, hard wall panels

Hard-sided trailer: A trailer with foldable, hard wall panels

Hard shoulder: A part of the road that is divided by broken or continuous yellow lines from the rest of the road and should be used only by certain road users in certain situations

Hard solder: Uniting two pieces of metal with a material having a melting point higher than soft solder e.g., silver soldering

Hard spots: Shiny bluish/brown glazed areas on a brake drum or disc friction surface, caused by extreme heat. Excessive heat has changed their molecular structure. Hard spots can usually be removed by resurfacing

Hard stop: Hard braking, but not necessarily with locked wheels

Hardtail: A term for a bike (motorcycle or bicycle) which has no rear suspension

Hardtop: Hardtop

A two-door or four-door vehicle without a center door post, i.e., no B-post. It gives the impression of uninterrupted glass along the side of the car. The term is derived from Hardtop convertible. Other generic names have included sports coupe, hardtop coupe, or pillarless coupe. In the face of proposed rollover standards, nearly all automakers turned away from the pillarless design to a pillared version by 1976-77.
Also See
Colonnade Hardtop
Formal Hardtop
Four-door Hardtop
Four-door Pillared Hardtop
Two-door hardtop

Hardtop convertible: An automobile with a fixed roof that does not retract into the Trunk, but gives the appearance of being a Convertible

Hardtop stand: A foldable stand that holds a detached hardtop in a vertical position when stored

Hard-top trailer: Hard-top trailer

A vacation trailer with a hard top and (most often) canvas sides.

Hard trim: Instrument panel moldings, center consoles and similar plastic trim

Hardy disc: A disc-style flexible coupling

Hardy-Spicer joint: A type of universal joint commonly used with prop shafts

Hardy-Spicer universal joint: A type of universal joint commonly used with prop shafts

Harley-Davidson: Click image for books on
Harley-Davidson

A motorcycle manufacturer

Harm: See
Bodily harm

Harmful: See
Ecologically harmful

Harmonic balancer: Also called Vibration damper. It usually is a solid Crankshaft Fan belt Pulley that has a weight ring bonded by rubber to the inner crankshaft-mounted ring. The outer ring absorbs and cancels out Crankshaft vibrations that otherwise might cause the Crankshaft to break. Formerly, two gearwheels carrying an unbalanced weight, mounted in bearings below the middle main crankshaft bearing, driven at twice engine speed and rotating in opposite directions to counterbalance the secondary vibrations in a four-cylinder reciprocating engine.

Also See
Crankshaft pulley
Damper

Harmonic balance wheel: A grooved wheel attached to the front end of the crankshaft which is connected by accessory belts to the fan, alternator, power steering pump, water pump, air conditioning compressor, and other devices so that the rotating crankshaft can drive these other parts as well. The crankshaft pulley usually has timing marks located on it, and these are necessary for checking and adjusting timing with a timing light.

Harmonic Distortion: See
Total Harmonic Distortion

Harmonic voltage: A voltage whose frequency is a multiple of the fundamental frequency.

Harness

A belt system used with child seats and in cars, consisting of two shoulder belts and two lap belt portions fastened by a central buckle.
A bundle of electrical wires. For convenience in handling and for neatness, all wires going to certain part of the vehicle are bundled together into a harness. A Wiring harness.

Also See
Four-point Racing Harness
Brinell hardness
Wiring harness

Harness Connector: See
Wiring Harness Connector

Harness ties: Self-tightening nylon straps used to bundle wires into harnesses. Once tightened, they can't be removed unless they are cut

Harness wrap: One of several materials used to bundle wires into manageable harnesses

Also See
Loom
Split loom
Loom tape
Harness ties

Harvey wallbanger: Trucker slang for a reckless driver as in "That 4-wheeler is a real harvey wallbanger."

Hat: The portion of a detachable brake disc that comes in contact with the wheel hub
Also see
Rotor Hat

Hatch

The rear opening of a vehicle which allows passage into its cab.
A Hatchback.
A Tailgate.
An opening in a deck through which cargo and stores are loaded or unloaded.

Also See
Cross-hatch
Hot hatch

Hatchback: Hatchback

A car design in which the rear Trunk and lid are replaced by a rear hatch that includes the Backlight (i.e., rear window). Usually the rear seat folds down to accommodate more luggage. Originally a hatch was a small opening in the deck of a sailing ship. The term hatch was later applied to airplane doors and to passenger cars with rear liftgates. Various models appeared in the early 1950s, but weather-tightness was a problem. The concept emerged again in the early 1970s, when fuel economy factors began to signal the trend toward compact cars. Technology had remedied the sealing difficulties. By the 1980s, most manufacturers produced one or more hatchback models, though the question of whether to call them two-door or three-door never was resolved. Their main common feature was the lack of a separate trunk. Liftback coupes may have had a different rear-end shape, but the two terms often described essentially the same vehicle.
Also See
Five-door hatchback
Four-door hatchback
Liftback station wagon

Hatchback coupe: Hatchback coupe

Originally a small opening in the deck of a sailing ship, the term hatch was later applied to airplane doors and to passenger cars with rear liftgates. Various models appeared in the early 1950s, but weather-tightness was a problem. The concept emerged again in the early 1970s, when fuel economy factors began to signal the trend toward compact cars. Technology had remedied the sealing difficulties. By the 1980s, most manufacturers produced one or more hatchback models, though the question of whether to call them two-door or three-door never was resolved. Their main common feature was the lack of a separate trunk. Liftback coupes may have had a different rear-end shape, but the two terms often described essentially the same vehicle.
Also See
Three-door hatchback coupe
Two-door hatchback coupe

Hatch battens: Flat bars which are wedged against hatch coamings to secure tarpaulin

Hatch beam: Portable beam across a hatch to support hatch covers

Hatch coaming: The vertical plating bounding a hatch for the purpose of stiffening the edges of the opening and resisting water entry

Hatched marking: Chevron markings on the road which help separate traffic lanes

Hatchway: An opening in a deck through which cargo and stores are loaded or unloaded

Hat section: See
Top hat section

Haul: See
Long-haul

Haul Distance: See
Average Haul Distance

Hauling: See
Compensated Intracorporate Hauling
Intracorporate Hauling

Hauling snow: The loading, removing, and disposing of snow piles after snowplowing operations

Haul road: See
access road

Hawse pipe: Tube through which anchor chain is led overboard from the windlass on the deck

Hawser: Strong rope or steel cable used for securing or mooring ships

Hazard: Anything that could be a source of danger on the road
See
Road hazard

Hazard flasher switch: A switch (usually located on the steering column below the steering wheel) which makes all the signal lights flash simultaneously, to warn other vehicles that your car is disabled or going very slowly down the road. Also called 4-way warning light switch.

Hazardous location: Any area or space where combustible dust, ignitable fibers, or flammable, volatile liquids, gases, vapors or mixtures are or may be present in the air in quantities sufficient to produce explosive or ignitable mixtures.

Hazardous wastes: Automotive wastes that are on the EPA's list of hazardous materials or that have one or more hazardous characteristics

Hazard warning flasher: Actuates warning system of flashing front and rear turn signal lamps

Hazard warning switch: A switch (usually located on the steering column below the steering wheel) which makes all the signal lights flash simultaneously, to warn other vehicles that your car is disabled or going very slowly down the road. Also called 4-way warning light switch.

Hazmat: Hazardous materials, as classified by the U.S. Environmental Protection Agency (EPA). Transport of hazardous materials is strictly regulated by the U.S. Department of Transportation.