Tire Parts: What are the Different Parts of a Tire?

Understanding proper tire maintenance, selection, and safety start with knowing the basics. Why are tires important? How do I choose the right set for my vehicle?

Tires are a driver’s first and only contact with the road, transferring actions such as steering, braking, accelerating, and turning. They are specifically chosen for each vehicle, making tires one of the most important safety features on a vehicle.

Parts of a Tire

tire parts diagram

Tire Bead

A rubber-coated loop of high-strength steel cable that allows a tire to stay “seated” on a rim.

We’ll start from the inside out! Tire beads hold the tire to the rim or the outer edge of the wheel. They’re made of copper, brass, or bronze-plated high tensile steel wires wound into a rubber band. Tire beads prevent the tire from sliding out of place when the wheel rolls.

Tire Bead Filler

Bead filler is a rubber compound inside the tire’s beads. It provides stability to the lower sidewall and bead area. The density and stiffness of a tire’s bead filler help to determine a tire’s performance characteristics.

Tire Body Plies

This is the tire itself, made up of several layers of plies. Plies, like polyester cord, run perpendicular to the tire’s tread and are coated with rubber to help bond with other plies and belts to seal in the air. Plies give tires strength and resistance to road damage.

The cord body gives the tire strength and transmits cornering forces from the tread to the wheel. Rubber-coated fabric cord, called body plies, make up the cord body. Body plies can be made of polyester, rayon, or nylon. Polyester is most commonly used.

Tire Inner Liner

This is the innermost layer of a tubeless tire that prevents air from penetrating the tire.

The inner liner (in the center of the tire diagram) is a rubber compound bonded to the inside of the cord body that retains air under pressure. It has no cord reinforcement, and it functions as an inner tube. Note, however, that modern car tires no longer have inner tubes inside them. A tire’s beads, bead filler, and inner liner work together to hold air within the tire walls.

Belt Plies

Belt plies are two or more strong layers of cord just under the tread area of the tire. The primary function of belt plies is to provide strength and stability to the tire tread. They play a role in improving tire mileage, impact resistance, and traction. Steel is the most common cord material used in belt plies.

Tire Sipes

Sipes are special treads within the tread that improve traction on wet, dirty, sandy, or snowy road surfaces.

Tire Grooves

The spaces between two adjacent tread ribs are also called tread grooves. These allow water to escape effectively.

Tire Shoulder

The outer edge of the tread wraps into the sidewall area.

Tire Sidewall

The sidewall of the tire protects cord plies and features tire markings and information such as tire size and type.

The area of a tire from the bead to the tread on the side of the tire is called the sidewall. It forms a protective covering for the cord body. Information about the tire is printed on the sidewall. This information includes the tire size, load index, and speed rating. Sidewall rubber compounds are designed to resist damage from ozone, cuts, and snags.

Tire Tread

The portion of the tire that comes in contact with the road.

The tread is the portion of the tire that comes in contact with the road surface. The tread’s compound and its design have to balance wear, traction, handling, fuel economy, resistance, and other characteristics of the tire. Tread designs vary greatly!

For example, Destination LE2 all-season tires need to perform well in both wet and dry road conditions. They have circumferential tread grooves. These grooves allow water to pass through and stay off the tread.


What are the parts of a tire?

Tires are made up of many different parts, and it’s important to understand how they work.

  • Belts.
  • Sipes.
  • Tread.
  • Grooves.
  • Shoulder.
  • Sidewall.
  • Inner Liner.

What are the 4 parts of a tire?

  • Tire Shoulder. The outer edge of the tread that wraps into the sidewall area.
  • Tire Sidewall. The sidewall of the tire protects cord plies and features tire markings and information such as tire size and type.
  • Tire Body Plies. This is the tire itself, made up of several layers of plies.

What is the part called that holds the tire?

A wheel has an inner and outer rim to hold the tire. The center hole in the wheel fits over the axle hub, and it’s the part that supports the vehicle’s weight. The smaller holes around it go over the wheel studs.

What are the six basic parts of a tire?

Regardless of the tire category type, all passenger cars, SUVs, CUV, and light truck tires share certain basic components.

  • Beads. We’ll start from the inside out!
  • Bead Filler. Bead filler is a rubber compound inside the tire’s beads.
  • Radial Cord Body.
  • Inner Liner.
  • Belt Plies.
  • Sidewall.
  • Tread.

What are the screws on a tire called?

Wheel studs are the threaded fasteners that hold on the wheels of many automobiles. They are semi-permanently mounted directly to the vehicle hub, usually through the brake drum or brake disk. Lug nuts are fastened onto the wheel stud to secure the wheel.

What’s the shoulder of a tire?

The Shoulder is the area where the tread and sidewall meet, including the tread blocks nearest the side of the tire (beginning outside the outermost water channel) and the area transitioning to the side of the tire where tread grooves are still visible.

What is the thing above the tire called?

The wheelhouse is the portion of the body located above your car’s tires.

What is a fender liner?

A fender liner, AKA inner fender liner, is simply a plastic barrier between the fender and the engine, and it comes installed in most modern cars. Each front wheel has a separate fender liner.

What are the parts of a wheel and axle?

A wheel and axle are one of six types of simple machines and consist of an outer ring or cylinder called the wheel and an inner ring or cylinder called the axle. These two parts are rigidly connected and move together in the same direction when a force is applied to either the wheel or the axle.

What is the hub of a wheel?

Wheel hubs are located in the center of the car’s wheels. Specifically, you can find them situated between the drive axle and brake drums. Essentially, wheel hub assemblies work to connect the wheel to the vehicle body. The assembly contains bearings, which allow the wheels to roll quietly and efficiently.

What is a tire casing?

The tire casing is the body of the tire and includes components such as the Bead, Sidewall, Body Ply, and Inner liner. Basically, everything except the Tread and Belt System.

What type of rubber is used in tires?

The two main synthetic rubber polymers used in tire manufacturing are butadiene rubber and styrene-butadiene rubber. These rubber polymers are used in combination with natural rubber.

What is the most important part of a tire?

One of the most important parts in the construction of the tire, the body ply, is located beneath the steel belts. The body ply is typically a sheet of polyester material topped with a bit of rubber. The body ply is integral to helping the tire bear weight and holds its shape.

What part of the tire is the bead?

The bead sits at the inner lip of the tire that meets the wheel, opposite of the tire’s tread. Imagine a tire without a wheel. The bead is easy to spot on a dismounted tire as it sits at the base of the sidewall and has a slightly wider profile.

How Much Does It Cost to Replace a Fender Liner?

Prices for replacement inner fender liners range from less than a dollar for a single unit and up to $730 for a set of four. Replacement fender liner costs largely depend on the part’s compatibility with your vehicle’s year, make, and model.

How much does a fender liner cost?

Fender liners can cost anywhere between $3 and $400. They can come individually or in pairs.

How many parts are in an axle?

They have four main parts, which are the beam, the swivel pin, the track rod, and the stub axle. Front axles must be as sturdy as possible, and that’s why they’re usually made from carbon steel or nickel steel.

What is the tire construction?

Tire construction is a mix of layers consisting of different complex materials. Many raw materials are combined to produce rubber compounds to meet specific characteristics. Depending on where in the tire and what function the rubber will be required to perform determines the rubber compound that will be used.

Why are all tires black?

The rubber that tires are sourced from is a milky white color, but carbon black is added to the rubber as a stabilizing chemical compound and makes the tire black. Carbon black is combined with other polymers to create the tire’s tread compound.

What is the part that holds the tire called?

The Rim. If the tire is the skin, then the rim is the skeleton of the wheel assembly. The tire wraps around the rim, and it supports the tire, giving it form and allowing air to fill it. Rims are typically made from steel or aluminum and come in hundreds of different styles.

What is the metal part of a tire called?

Casing. The second layer consists of parallel fabric/metal cords called casings which provide the substructure for the tire. The careful orientation of these cords helps to prevent the rubber from stretching or breaking.