Wheel Glossary
A
Acrylic Clearcoat:
A clear top coat that is specified for use on certain wheels.
Aftermarket Wheel:
These are custom wheels that car owners can buy to enhance the look of their vehicles. These are not Original Equipment wheels.
Anodized Wheel:
These wheels have a tinted look, usually gold, but they are not painted. The tint is from a very thin layer of metal that is electrically deposited on the wheel.
As Cast Wheels:
The windows of these wheels are not painted. The aluminum, as it is cast in the mold, is visible under the clear coat.
B
Back Spacing:
A method used to determine the offset of a wheel. The measurement is taken from the mounting surface of the wheel to the lip on the inner flange. The best way to measure it is to put a straight edge across the back flange and use a tape measure to measure the distance to the mounting flange.
Bead Seats:
The area on the outside diameter of the wheel where the tire makes contact and forms a seal. Transwheel does not repair damage between the bead seats.
BFC:
Bent From Center. This is usually referred to as Lateral Run Out and can sometimes be repaired.
Blasting:
One method of removing paint and clearcoat from a wheel.
Blemish:
A finished wheel that has an unrepairable cosmetic defect on the face. They are sometimes called "blems," and may be sold as a "second." Cosmetic defects only affect appearance, not the integrity of the wheel.
Bolt Pattern:
The spacing, in inches or millimeters, between the lug holes. On wheels wih four (4), six (6) and eight (8) lug holes, measure the lug holes directly across from each other. On wheels with five (5) lug holes, skip one lug hole.
Brinell Hardness Test:
A test used to determine the hardness of forgings and castings and may correlate to tensile strength and ductility of a wheel.
BTB:
Bent Too Badly. When the flange of a wheel exceeds the range where it can safely be repaired.
Buffing:
The process of sanding out surface defects in a wheel's clearcoat, and then using a buffing compound to restore the high gloss finish.
C
Center Cap:
The decorative cap found in the center, or hub of a wheel. It usually snaps in place, but may be bolted on, or held in place by screws.
Chrome Wheels:
These wheels are not painted or polished, but have a thin mirror-like metal (chromium) finish electro-chemically deposited on the surface.
Chrome (Custom):
A wheel that has been chromed by LKQ. These wheels do not come chromed from the factory as an option.
Chrome (O.E.):
A chromed wheel that is offered from the manufacturer as an option.
Clearcoat:
The high gloss top coat that is applied to a wheel as the final refinishing step. This is a usually a clear polyester powder coating, but may also be acrylic powder or a liquid.
Corrosion:
Aluminum may oxidize when exposed to moisture, salt and certain chemicals. This discoloration is called corrosion, and is commonly found on wheels when the clearcoat fails or is damaged due to improper wheel weight installation or road damage.
Cosmetic Damage:
Damage that affects the appearance of the wheel, but not the structural integrity of the wheel.
D
Deburring:
After machining, the windows of the wheel may have sharp edges, or burrs. These sharp edges need to be removed before clearcoating to prevent corrosion. The process of removing sharp edges is called deburring.
Directional Wheels:
These wheels have a pattern, usually spokes, that are oriented toward a specific direction. Because of this, wheels that mount on the left side of a car would appear backwards when mounted on the right side, and vice versa. These wheels are designated with either (R) or (L). Note: tires can also be directional.
Drop Well:
The area located on the outside diameter (OD) of the wheel that is designed to allow the tire to be mounted with greater ease.
F
Face:
The outside part of a wheel. The area that is visible when mounted on a car.
Flange:
The vertical edge of the wheel that keeps the tire securely on the wheel. The outboard flange is on the face of the wheel. The inboard flange is opposite the face.
Flange Cut:
This is a wheel that is machined on the flange area only. The rest of the face is usually painted.
G
Gold Tint:
A gold tinted topcoat used on some wheels instead of the regular transparent clearcoat.
H
Hand Painting:
Accent painting that is applied to the wheel.
Hub:
This is the center area of the wheel. The lug holes are located in the hub area.
I
ID:
Inside Diameter. The inner circumference of the barrel of the wheel.
Inserts:
Splined, steel inserts that are pressed into the lug holes of some aluminum wheels to form the surface the lug nuts are tightened onto according to proper torque specifications.
L
Lip:
The outermost edge of the flange. Usually the wheel weights are attached at this point. LKQ does not recommend putting any type of wheel weight on the face of the wheel. This will void LKQ's warranty
Lip Cut:
These are wheels that have only the lip machined. The rest of the wheel is painted.
Lug Holes:
These are the holes in the hub area where the lug studs pass through the wheel. Lug holes can sometimes get elongated from improper lug tightening procedures and incorrect torque specifications. Elongated lug holes cannot be repaired.
Lug Nuts:
These are heavy threaded nuts that screw on the lug studs, fastening the wheel to the vehicle. Use the Torque specifications listed for your vehicle.
M
Mag Wheels:
Alloy wheels with a high magnesium content. Generally lighter than standard aluminum alloy wheels.
Matte Finish:
A low gloss, or dull, clear top coat found on some wheels.
Mottling:
This is a casting defect that is sometimes found in the metal of aluminum wheels. When machined, wheels with mottling will exhibit a blotchy look, similar to water spots, on the surface.
Mounting Surface:
This is the flat surface on the back side of the wheel. This surface mounts to the hub of the car.
O
OD:
Outside Diameter. The outer circumference of the barrel of the wheel.
O.E.M.:
Original Equipment Manufacturer. Typically used to describe parts of a vehicle that were originally designed for the car.
Offset:
A measurement often used to distinguish wheels of similar design. It is the distance from the center line of the wheel to the mounting surface on the inside of the hub. A positive offset has the mounting surface outside the center line, and a negative offset has the mounting surface inside the center line.
P
Polished Wheels:
These wheels have areas that are polished to a high luster before being clearcoated. Similar to, but not as bright as, a chromed wheel.
Porosity:
This is a casting defect where small pockets of air are trapped in the aluminum as it cools. The machining process can open up these voids, resulting in bubbles in the clearcoat. There is no way to correct this condition if it is found in a wheel. Porosity only affects the appearance of the wheel, not the integrity.
Powder Coating:
A method of coating wheels by applying powdered paint. The powder melts out to form a film and is baked to a very durable finish. Most of the metallic base coats we apply are powder coatings, and most of our wheels are top coated with a clear powder coating.
R
Rivets:
Inserts found on the face of a wheel, they are usually made of either plastic or aluminum. Rivets are generally decorative, and not functional, on one-piece wheels. However, some two-piece and three-piece wheels are held together by rivets.
Runout (R/O):
The degree to which a wheel is out of round as measured with a dial indicator placed on the OD.
S
Service Wheels:
Wheels manufactured by the OEMs that are sold as replacements.
Smoke Tint:
A charcoal tinted topcoat that is used on some wheels instead of the regular transparent clearcoat.
Spokes:
Common structural feature of aluminum wheels. Spokes radiate outward from the hub to the flange and may be straight, or curved in either direction. The number of spokes is often used to identify a wheel.
Stickers:
Decorative decals that are placed on the face of a wheel before clearcoating.
Structural Damage:
This type of damage may affect the integrity of a wheel, and therefore, is not repaired by LKQ. Generally, damage between the bead seats, or damage to the hub and lug hole areas is considered structural.
T
Take Offs:
OEM wheels that are removed from a car in favor of aftermarket, or other OEM style wheels. These wheels typically have very little damage, if any, and have little or no miles on them.
Texture:
This is the rough surface found on the face or in the window of a wheel.
Two and Three Piece Wheels:
Wheels that are fabricated from two or three separate pieces, rather than being cast as one unit. The flanges of these wheels are often thinner, and easily bent.
V
Valve Stem:
This is the valve that is inserted through the wall of the rim and used to inflate the tire. The valve stem hole is the hole the valve passes through.
W
Weld Blush:
Commonly known as weld marks or shadowing. This is the discoloration that sometimes occurs when a wheel is welded. It is caused by a slight difference in the composition of the two alloys.
Window:
The pattern of open spaces found in the structure of a wheel. (Not lug holes). The windows of most wheels are painted before machining.
Wheel Cover:
Decorative hub cap. Usually found on steel wheels.
Wheel Weights:
These are lead weights attached to the inboard and outboard flanges of a wheel to bring the wheel and tire into balance. LKQ recommends stick-on, rather than clip-on weights, since these do not promote corrosion on the wheel.
Z
Zyglo:
A dye penetrant that glows under UV light. It can be used to find cracks in aluminum wheels.
