June 2021

From commuter sedans to long-haul trucks, tires are essential to everyday life. At FlexTrades, our skilled technicians travel across the country to support U.S. manufacturers — and many of them drive thousands of miles to reach their assignments. So when it comes to the reliability of tires, we don’t take it lightly.

In fact, we support several leading tire manufacturing clients nationwide, providing the talent that helps keep production lines rolling. That’s why, in this edition of How It’s Made, we’re exploring the process behind the rubber that meets the road.

Tire Materials

Tire manufacturing starts with a mix of natural and synthetic materials, blended for strength, flexibility, and durability.

Natural Rubber
Synthetic Rubber / Polymers
Steel Wire: Used in belts, beads, and truck tire plies
Textile Cords: Provide structural support within plies
Fillers: Carbon black and silica, used to reinforce rubber during the Banbury mixing process
Antioxidants & Antiozonants: Protect the rubber from heat, oxygen, and ozone damage
Curing Additives: Sulfur and zinc oxide, key ingredients during vulcanization

Rubber Manufacturing Process

There are three key operations used to prepare rubber for tire building:

Banbury Mixing: Raw and synthetic rubbers are mixed with fillers under heat and pressure to form solid, workable rubber
Extruding: Shapes the rubber into usable forms
Calendering: Layers rubber with fabric or steel to create belts, plies, and edge covers

Once processed, the material is cut, sheared, spliced, or shaped to exact specifications — ready for tire construction.

Tire Components

Every tire is made of multiple layers, each with a specific purpose:

Innerliner: Keeps air sealed inside the tire
Plies: Provide strength and hold air pressure
Bead: Ensures an airtight seal with the wheel
Sidewall: Protects the structure from road and curb damage
Belts: Add strength to the tread and improve performance
Tread: Provides grip, traction, and durability

How Tires Are Made

The tire-building process happens in two stages on highly specialized machinery, such as:

Tire Building Machine (TBM)
Tire Assembly Machine (TAM)
Tire Forming Machine (TFM)
1st and 2nd Stage Machines

These may be manually operated or fully automated depending on the facility.

Stage One: Casing Building

This step forms the base structure of the tire — also called the carcass. It includes:

Wrapping the innerliner onto the drum
Layering body plies over the innerliner
Placing the beads at each side
Inflating the drum bladder to shape the plies over the beads
Adding and pressing sidewalls into place

Stage Two: Tread & Belts Application

The carcass moves to a second machine where steel belts and tread are added. At this point, it’s known as a green tire — shaped but not yet cured or hardened.

Curing the Tire

The green tire is placed into a curing mold, which functions like a large clamshell. A bladder inside the mold inflates with steam, pressing the rubber into the mold to form the tread pattern and sidewall lettering.

Passenger tires cure for 10–15 minutes at 300°F
Heavy-duty or off-road tires may cure for 24 hours

Once cured, the tire is cooled on a Post-Cure Inflator (PCI) to stabilize its shape before inspection.

Inspection & Testing

Every tire undergoes strict quality control to ensure safety and performance.

Tire Uniformity Testing: Measures balance and roundness under simulated road conditions
X-Ray Testing: Detects internal flaws
Destructive Testing: Verifies structural limits under extreme stress

After passing all inspections, the tire is ready for the road.

For a closer look, watch this Tire Manufacturing Video. And if you’re curious about tire care, check out our article on safe driving and tire maintenance.

Safe travels!

The pandemic disrupted the global workforce in ways few could have predicted. Now, as industries rebound and evolve, many workers are rethinking their future — and if you’re one of them, it might be time to consider a career in manufacturing.

At FlexTrades, we believe in the power of skilled trades to provide growth, advancement, and long-term stability. One of the most promising career paths in this space is in CNC machining and programming — a field with strong demand, competitive wages, and clear opportunities for advancement.

Whether you’re just starting out or looking to level up, here’s how you can carve out your path to becoming a CNC Programmer, starting from the ground up.

Step One: CNC Operator

Getting started doesn’t require decades of experience. Here are three common ways to launch your CNC career:

Go Back to School: Enroll in a technical or trade school with an accredited Machine Tool or CNC Manufacturing Technology program. You’ll build a strong foundation in both theory and hands-on skills — including safety, print reading, machining techniques, and quality control.

Become an Apprentice: An apprenticeship with a local manufacturer gives you real-world experience. Whether it’s short-term or leads to full-time work, make the most of it by learning everything you can and building relationships.

Start Entry-Level: Find a nearby manufacturer using CNC equipment. Even if they’re not hiring operators, apply anyway. Be willing to start in another role and work your way up. Express your long-term interest in CNC from the start.

Once you’re in, show up, speak up, and keep learning. The manufacturing floor rewards initiative and consistency.

Step Two: CNC Machinist

As a CNC Operator, your job is to load materials, run the machine, monitor operations, and inspect finished parts. But when you’re ready to step up, your goal is to become a CNC Machinist — someone who sets up and configures machines for each new job.

To make that move:

Ask questions and learn from your team — coworkers, leads, supervisors, anyone who’s done the job before
Observe setups, take notes, and look for opportunities to shadow
Do your research. Understand the steps involved in setups and study tooling and processes
Request hands-on training and be proactive when a gap appears
Pursue certifications from organizations like NIMS to solidify your credentials

When a skilled machinist retires or advances, be ready to step in. Let your leaders know you’re prepared and committed.

Step Three: CNC Programmer

Programming is where art meets precision. To reach this level, build on everything you’ve already done — and take it further.

To become a CNC Programmer:

Master G & M Code — it’s the core language of CNC operations
Study CNC tooling to understand what tools to use, when, and why
Consider buying your own seat in CAM software like Mastercam or Fusion 360 to practice at home
Enroll in a CNC Programming course at a local technical school
Take advantage of online training options — many software vendors offer detailed, video-based instruction (like Mastercam University)

The more you learn, the more valuable you become — not just as a programmer, but as a problem-solver and leader on the floor.

Keep Growing with FlexTrades

Once you’re a skilled CNC Programmer, your path doesn’t end. The world of advanced manufacturing is constantly evolving, and so are the machines, materials, and software behind it.

That’s where FlexTrades comes in.

As a CNC Operator, Machinist, or Programmer working with FlexTrades, you’ll get to travel the country, work on cutting-edge equipment, and gain exposure to new technologies across industries. You’ll sharpen your skills and expand your experience while helping American manufacturers grow.

Just starting out but recently graduated from a technical school? Join the FlexTrades ReTool Team. We help new grads get hands-on experience that complements classroom learning and sets you up for long-term success.