Every community and industry has terminology and expressions that it uses in its own idiosyncratic manner. Classic vehicle restoration, maintenance and ownership is definitely no exception!

It's easy for the incompletely initiated to get led astray, so here's the It's My Classic pictionary-dictionary, explaining some of the terminology you may stumble across.

Learning from the OED's example, we accept that this is going to be an ongoing process, and may even take years to complete. If you have any additions, we'd love to hear from you.

Classic car at Oulton Park

A- B- and C-pillars

Starting at the front of a car and working towards the rear, there are commonly three uprights on each side that stop the roof falling on your head. A-pillars are at the front, holding the side of the windscreen and acting the front roof support. B-pillars are in the middle, and C-pillars hold up the back and the rear screen.

Bommy knocker nylon mallet

Bommy knocker

Originally a type of a medieval weapon, these days the term bommy knocker has a different meaning. Essentially it's a kind of hammer, but with a nylon head. Nylon doesn't 'bruise' metal that's being persuaded into a new shape in the way a steel-on-steel impact tends to.

Studebaker Champion front brightwork


Essentially, this is the bling - the shiny, usually chromed, bits that are added to a vehicle to accentuate lines or enhance its appearance, such as chrome strips, headlight surrounds, bumpers or grilles.

Single SU carburettor annotated pic.gif


Nope, this has nothing to do with energy-giving foods. It's automotive short-speak for a carburettor. You'll find a beginners introduction to carbs here.

Triuph Herald chasis


This term comes from French so, unless you're from the USA, the 'ch' in chassis is soft (like in champagne, not hard as in chance). Whichever, it's a structural framework, usually made of steel, which carries the loading of the vehicle and to which the bodywork is attached.

Clevis Pin


This might sound like it's related to a famous Scottish mountain, but a clevis pin is actually a kind of fastener that is held in place by a pin (usually a split pin) through the bottom end, allowing it or the part it is fixing to rotate.

Bentley  Tourer 1931 engine.JPG

Compression ratio

The compression ratio is a way to desrcibe and quantify the the amount by which the charge if fuel and air is compressed by the piston before it is fired by the spark plug. As a general rule of thumb, the higher the ratio, the greater the power developed by the exploding fuel/air mixture and the more efficient the engine.

Rear differential


If you're an IT geek, you may think diffs are data conversion tools. Nope. Diff is short-speak for a differential. It's the part of a vehicle's drivetrain that enables one wheel to spin faster or slower than the one connected to it on the opposite corner - so you can drive around corners.

Classic car distributor on engine


This doesn't mean the sensation of feeling like you're spinning around. It's a common short-hand term for a distributor, which takes high voltage current from the ignition coil and sends it on to the spark plugs in an approprite sequence so that firing happens in the correct order.

Panel beating Dollies


Forget the vaguely human-like toys that stereotypical little girls are expected to play with, these are shaped blocks of steel that are used in conjunction with shaping hammers and act as a miniature anvil when panel beating.

Singer Junior 1932


This is a difficult one, as it's almost exclusively context-dependent. It usually requires a degree of familiarity with the job in hand and/or the person attempting to undertake that job whilst trying to also find appropriate wording to describe the tool or part needed.

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Friday Car

In the good and not-so-good old days of British Leyland, the quality of some cars coming off the production lines wasn't always as great as their customers might have hoped. These reliability issues led to some fairly sour jokes about 'Friday cars' - cars that had been thrown together in a hurry when the workers (supposedly) just wanted to finish early and go home.

Grub screw

Grub screw

OK, so it's an unappetising name, but grub screws are really useful little things. They're perfect for fixing parts in place where you don't want a bolt or set-screw head getting in the way. They are a headless set-screw that you tighten with a hexagonal Allen key.

Ball pein hammer


Don't force it, use a bigger hammer! A hammer is not the same as a bommy knocker. A hammer has a flattened steel head. The variety shown here is a ball pein hammer. If it has a split 'claw' on one end, it's a claw hammer. Claw hammers are used for nails and should go nowhere near your precious vehicle (unless it has a wooden frame, of course!).



Cough, bang, wallop! A misfire is what happens when there is unburned fuel and air left in an engine's cylinder after the rest has been ignited, or if a cylinder has failed to combust at all. This can happen either at start-up or when the engine is running. A misfire can be caused by problems with the spark, with the fuel, or by mechanical issues.

Vincent motorcycle front shafts

Rake and Trail

Nothing to do with gardening, this is about motorcycle steering geometry. Rake is sometimes referred to as castor - the angle from vertical at which the headstock is positioned. Trail is determined by a straight line drawn through the centre of the headstock, through the centreline of the front axle, and carrying on to the ground, then measured back to the centre of whee the tyre meets the ground. Simple, wot?

Car engine rockers


The meaning of this term depends on which side of the Pond you come from. In the USA, what we Brits call a door sill, they call a rocker panel. In the UK, 'rockers' may be used to describe a style of music fan of yester-year, but it also refers to the rocker arm that opens and closes the valves in your engine. Mind you, it could be both music and engines - remember Madness and My Car?

Roll pin, spring pin, coiled spring pin

Roll pin

Put your pastry away, dear. I said roll pin not rolling pin. Also known as spring pins, slotted spring pins or coiled spring pins, these have an unsprung diameter larger than the opening in the parts they are intended to fasten together so that, when inserted, they spring outward and hold on nice and tightly.

Shaping hammers for panel beating

Shaping hammer

This type of hammer comes in a variety of different sizes and shapes. Some will have smooth surfaces, others will be textured. They are used in panel beating to shape sheet metals.

Skinpin inserted and held in steel panel


The term might sound like a particularly nasty form of torture (or a Liz Hurley dress style), but fear not. Skinpins are a type of temporary fastener used to hold sections of sheet steel together whilst they are being welded or riveted.

Split pins Cotter pins

Split pins

Split pins are, as the name suggests, fastenng pins (made from steel) that are inserted through a hole (e.g. in a castle nut or clevis pin) and one or both ends bent back to keep them in place. They come in lots of different thicknesses and lengths. Just to confuse things, in the USA split pins are called cotter pins

Tinworm rusty steel


The nemesis of all historic vehicles (and many a modern one too!), the dreaded tinworm attacks steel, oxidising it. Surface rust may not be appreciated by most of us, but it's only life-threatening if left unchecked and begins to damage structural integrity.

Tractor pull demonstrates torque


Torque is turning or twisting effort - it's the rotational equivalent of linear force - the effort required to turn something. In old money, it's measured in pounds per inch (inch-pounds). The old saying goes "horsepower tells you how fast you'll hit the wall, torque tells you how far you'll push it." Tractors and drag racers are probably the ultimate visual examples of automotive torque in action.

Prop shaft universal jiont


UJ - short for universal joint. You'll fiind them in places like the end of a prop shaft or in a steering column. They're used to couple two shafts that aren't in alignment so that both can move freely without losing too much torque.

Chicken investigating car wheel

Wheel tappers

Also sometimes referred to as the Wheel-tappers & Shunters Social Club - this is another term for those lovely people at VOSA who have the unpopular job of parking up in lay-bys and checking passing vehicles to ceck that they're not doing anything naughty, nasty or downright dangerous.

Pneumatic compressed air powered drill

Windy drill

This isn't a wind-up and nor is it anything to do with inclement weather or baked beans. 'Windy drill' is a term used to refer to a pneumatic (air-driven) drill. An air drill operates (usually) at much higher speeds than an electric drill.

Double wishbone on classic car


Forget chicken dinners and making wishes for the unattainable. This type of wishbone is made of steel, can be of the single or double variety (the picture here is a double wishbone) and forms part of some types of suspension.

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