AG TIRE TALK KEY TAKEAWAYS:
MICHELIN: “These are critical topics for anyone who works with or depends on tires for their livelihood….How to Read a Tire Identification Code, and how Ozone can affect tire life.”
BKT: “Tire manufacturers use a Tire Identification Code (a combination of letters and numbers, or alphanumeric) to identify the plant code, the week, and the year in which the tire is manufactured.”
YOKOHAMA TWS: “The Tire Identification Code will be located on the left side of the tire, near the tire name and down near the bead.”
MAXAM: “We recommend the following working solutions to help minimize ozone damage…ensure proper storage by placing tires in covered, enclosed, and well-ventilated dry areas away from direct sunlight…”
BKT USA, Inc.
Dave Paulk: Manager Field Technical Services
Tire manufacturers use a Tire Identification Code (a combination of letters and numbers, or alphanumeric) to identify the plant code, the week, and the year in which the tire is manufactured. If there is a manufacturing issue, this helps pinpoint the plant and week the tires were produced, ensuring that corrective actions are taken and necessary changes can be made. Agricultural tires typically don’t have unique serial numbers like cars (VIN numbers) or consumer goods that identify specific items.
In the example given below:
B is the internal plant code.
07 is the week the tire was produced.
24 means the tire was produced in 2024
If the week and date code consists of only three numbers, the tire was produced before 2000. Before 2000, the first two numbers represented the week of production, while the last number indicated the year code for that decade. Most odd-numbered decades had a triangle indicating it as an odd-numbered decade (1970s, 1990s).
If the tire is DOT rated, DOT precedes the plant and date code, as in the example below:
This can be seen on implement and farm highway service tires that are DOT rated. J is the internal plant code, and the tire was made in the 25th week of 2025. “FY” is the plant code assigned by the US DOT for DOT rated tires.
As a note of interest, DOT-rated agricultural tires are not necessarily the same as passenger car and light truck tires that are also DOT-rated. DOT-rated agricultural tires are made to run on the highway, but only for a limited amount of time, limited miles, and at limited speeds. If this is exceeded, they will get too hot and fail.
BKT has four assigned DOT plant codes that build DOT-rated tires. They are FY (Bhuj), 3V (Waluj), 9N (Chopanki, Bhiwadi), and 5P (Chopanki, Bhiwadi II).
Internal plant codes for all makes are J (Bhuj), B (Bhiwadi), A (Aurangabad), C (Chopanki), and F (Waluj). These plant codes will be followed by the four-digit date the tire was built.
Ozone damage to tires is generally caused by sunlight on volatile organic compounds (VOCs). There are many types and causes of VOCs, but some particularly common ones around the farm are petroleum fuel, hydraulic fluids, cleaning supplies, and pesticides.
Ozone cracking used to be especially prevalent in tires before some preventive measures were taken. Natural rubber used in tires is especially vulnerable to ozone cracking because of its chemical makeup. Ozone cracks form in objects under tension.
In tires, an antiozonant is added to the rubber before vulcanization to reduce the cracks caused by weather cracking or weathering. A common antiozonant used is a type of wax that bleeds to the surface and forms a protective layer. Other types of chemicals are also utilized. Butyl rubber is an ozone-resistant compound that is commonly used in inner liners for tubeless tires.
The best way to protect against ozone damage is to keep the tires covered or inside during extended times when the tires are not being used. Don’t store the equipment inside with petroleum fuels or oil, as this will cause the rubber to break down over time. Using the tire causes flex and will force the antiozonant to the surface. A tire that is not used will dry rot quicker than one that is used.
Yokohama TWS
Chris Neidert: AG Marketing, Training & Development Manager for Trelleborg & Mitas Tires – North America
I’m a big Seinfeld fan and to coin a phrase from Cozmo Kramer, “Without order, there is chaos.” Tire identification codes provide order.
Tire Identification Codes are used to identify where a tire company’s tire is produced and the age of the tire. Each manufacturer has their own nomenclature as to what the numbers and letters signify. Let’s review Trelleborg and Mitas ag tire identification code meanings. We call these production codes, and these are extremely important to read and understand because there are several reasons why we need to be able to interpret the code nomenclature.
- The most common reason we need the code is if the tire is being considered for a warranty, production location and tire age is needed.
- If tire testing is being conducted.
- In case of a tire recall.
Here is a chart showing some of the Mitas and Trelleborg Plant Codes.
Trelleborg and Mitas production code interpretation is the same. The first two characters of the code will identify the location of production. Most of the time two characters will be shown but some may have three. These characters will be followed by four numbers. These will identify the week and year of production.
First, let’s check out where the Trelleborg ag tire production code is located. If someone is calling me and asking for the production code location, I tell them if you are sitting in the cab the code will be located on the left side of the tire, near the tire name and down near the bead. Our red circle is showing the approximate location.
Here are some examples of the Trelleborg production codes. We will use the above chart to determine the production location and the age of the tire.
Production code information:
1H 0318
Produced in the Spartanburg South Carolina plant.
Produced during the 3rd week of 2018.
Production code information:
XC 0923
Tire is produced in the Tivoli Italy plant.
Produced during the 9th week of 2023.
Mitas production code sidewall location is not always in the same location, but the rationale is still the same.
As with the Trelleborg tires, we will use the above chart to determine the production location and the age of the tire.
Production code information.
UD 2023
Tire is produced in the Charles City, Iowa
Produced during the 20th week of 2023.
Production code information:
54 3322
Tire is produced in Octrokovice Czech Republic
Produced during the 33rd week of 2022
So, now you have some order in the world of tire sidewall nomenclature.
Michelin Ag
David Graden: Global Account Manager – Agriculture
As someone who’s spent years in the agricultural tire industry, I’ve had countless conversations about tire safety, performance, and longevity related to Michelin Ag tires. Two of the top questions I get asked are:
- How to read the Tire Identification Code (TIC) on the sidewall of an Ag tire?
- How ozone can affect tire life and how does this affect Michelin Ag tires vs competitors?
These are critical topics for anyone who works with or depends on tires for their livelihood.
How to Read the Tire Identification Code
Every tire sold in the US has a code molded into its sidewall. This code tells you where and when a tire was manufactured. For Michelin Ag tires, the last four digits of the code indicate the week and year of manufacture. For example, a code ending in “2319” means the tire was made in the 23rd week of 2019.
The first two characters are the plant code, which identifies the manufacturing facility. For Michelin agricultural tires, here are the plant codes for three of our key locations:
To find this code, look for the full code string on the sidewall – sometimes it’s only on one side of the tire. In my personal experience, it is always on the inside and very difficult to get to! The plant code will be the first part of that code.
Ozone Damage
Ozone damage, or ozone cracking, is a chemical reaction that occurs when tires are exposed to ozone (O₃) in the air. This gas reacts with the rubber compounds, especially when the tire is under tension, causing small cracks for form – usually in the sidewalls or tread grooves (passenger/truck tires). These cracks can grow over time and compromise the tire’s structural integrity.
Every tire brand will show ozone cracking differently under different conditions, however, in general an Ag tire has a “shelf life” between 12-14 years. It used to be common practice for tire dealers or farmers to purchase their Ag tires and store them for another 2-3 years, to allow them to “cure”. Unfortunately, due to environmental regulations enforced around 2007, tires are no longer made with those same chemicals that caused the rubber to harden over time, and they now begin to show ozone cracking sooner. In fact, in most cases where I have visited producers and tire dealers to discuss the possible warranty of a “good tire” that shows ozone cracking, I first educate them on how to read the DOT of that tire, then discuss how Michelin Ag tires are designed. Michelin Ag tires are typically designed with deeper and more vertical lugs than our competitors. With more useable 32nds of lug rubber and a more vertical lug shape, our tires will maintain better biting lug edges and traction for a longer period of time. By design, when a Michelin Ag tire reaches the end of its lifespan, there is often useable lug depth remaining and the operator of that machine is still achieving full efficiency. Unfortunately, the sidewalls are showing ozone cracking and the tire has reached the end of its life. This is a difficult concept to grasp, since we have all been conditioned to replace our tires when the tread is gone.
What We Can Do to Minimize Ozone Damage
At Michelin and across the industry, we take ozone degradation seriously. Here’s what I recommend to reduce the risk and stretch the life of your Ag tires:
- Store tires properly: store your loose tires in a cool, dry and dark place – away from electric motors or welding equipment that generate ozone and away from petroleum-based liquids (this will also cause rubber to become very brittle and break down).
- Store your machinery inside, away from sunlight and heat. If you must store your machinery outside, cover the tires to block out sunlight and reduce heat absorption.
- Remove weight and pressure: If you have the time and space, in the off season, reduce the air pressure and lift the weight off the tires. This will also reduce “flat spotting” over long winters.
- Never use petroleum-based chemicals: when cleaning your machine, only use soap and/or water to clean your tires. If you are showcasing your machine, and want to use some sort of tire shine, make sure it doesn’t contain petroleum.
In summary, understanding the Tire Identification Code and recognizing the signs of ozone damage are essential parts of tire safety and return on your investment. With the right practices, we can extend the life of our products and keep people safer in the field and on the road.
Maxam Tire International
Greg W. Gilland: Vice President Global Agriculture
The US Government through the Department of Transportation (DOT) requires markings on Off-the-Road (OTR) tries to include all pertinent work applications, such as mining, agricultural, forestry and industrial machines. This helps identify standards provided by the Tire and Rim Association of America.
To simplify things, here’s a summary of what the requirements are from the DOT on all passenger, service, utility, trailer, and commercial transportation vehicles:
- DOT Symbol and Tire Identification Number (TIN) are required to be conspicuously labeled on each sidewall of any tire with a Tire Identification Number (TIN) by permanently molding or laser-etching it.
- The DOT symbol is molded or etched into both sidewalls to indicate compliance with applicable US Federal Motor Vehicle Safety Standards (FMVSS).
- The Full TIN must be on one sidewall, and a partial TIN on the other or opposite sidewall.
- The TIN is a 10- to 12-digit code beginning with the code “DOT” to help identify the number sequence.
- The TIN is required for the purpose of recalling tires in case of a defect and must include the following with the number sequence: the manufacturer, facility (plant built), size (dimensions), type (characteristics), and finally week/year of manufacture to include “DOT” (the letters) that certifies the tire meets all required safety as well as performance standards.
- The TIN marking location is based must be between the bead and a point halfway from the bead to the shoulder of the tire.
- Any “retreaded” tires must have a new TIN assigned by the tire retreader, replacing the original as the new manufacturer of the tires bearing the quality and product liability.
Note that all off-the-road manufacturers are advised to provide a commercial or written statement as proof that the tires were manufactured and sold for the expressed use. This ensures that these off-the-road specialty tires are not “rated” for continuous on-road use other than for limited to short distance movement from site to site. For this reason, specialty tires are labeled according to the tire industry, issued by the Tire & Rim Association of America (T&RA), the European Tire and Rim Organization (ETRTO), and the Japan Automobile Tyre Manufacturers Association (JATMA).
As the serial number requirements are not uniformly mandated, all off-the-road tire manufacturers can serialize tires in any format that meets their standards. MAXAM’s off-the-road serial number encompasses all the requirements below in its coding:
- MAXAM Tire Factory code for location and country.
- The tire manufacturing or production Week and Year.
- Specific Compound or Tread Design differences within a product family.
- Any additional coding for that number sequence to distinguish between one product batch and another.
MAXAM uses each product serial number in the following ways:
- Identify specific tires for product field testing, performance comparison or operating cost field evaluations.
- Identify the tire for the purpose of warranty management and customer credit tracking.
- Traceability for any product failures caused by a production defect for each unique tire or for a serial batch of numbers.
- Traceability for each factory quality control system.
Serial number tracking is commonly used on tires that are exposed to ozone cracking, or when a mounted tire has been exposed under direct sunlight for extended time and has deteriorated.
In short, tire ozone damage is an atmospheric effect caused by prolonged exposure to sunlight, degrading the rubber compound in the tire. This effect knowns as “chain scission” – a loss of the rubber integrity, resulting in the tire have discoloration, cracks on tread or sidewall of the tires, flaking. These symptoms all indicate the degradation of the tire, indicating potential premature failure.
Other factors that can also exacerbate a tire with ozone cracking include:
- Poor inflation maintenance, leading to high heat generation.
- Extreme temperature fluctuation
- Prolonged exposure to high ozone-generated equipment, such as electric motors, welding equipment, and long-term exposure to battery chargers operating nearby.
MAXAM recommends the following working solutions to help minimize ozone damage:
- Ensure proper tire storage by placing them in covered, enclosed, and well-ventilated dry areas away from direct sunlight.
- Store tires as far away as possible from ozone-generating equipment and tools such as welding equipment or large electric motors in constant operation.
- Keep tires stored away from extreme temperature fluctuations, such as high heat or extreme cold.
- Tires mounted on equipment for extended periods of time need to have their inflation pressures checked, minimizing the effect of ozone deterioration and ensuring casing integrity.
- Tires mounted on idle vehicles for extended periods of time should be stored in covered parking, reducing the impact of direct sunlight.
- Regularly inspect tires for signs of ozone degradation such as discoloration, tread cracks, rubber flaking, or loss of causing integrity.
All information is provided in this blog solely to provoke thought. All deductions made from information on this site must be confirmed by Certified Ag Tire Dealer & Tire Manufacturer before use. Ag Tire Talk does not recommend anyone conduct tire service work with exception of Certified Ag Tire Dealer Professionals.