Tire Safety: Expiration Dates

Imagine cruising down the road on a beautiful spring afternoon or returning home after a long day at work when suddenly the back right tire of your vehicle explodes. Luckily, you maintain control and safely maneuver to the side of the road. The tires are new, purchased a few months ago from a local tire shop. How could this happen to new tires?

The fact is that all tires have an expiration date. Surprisingly, many consumers and sellers of tires do not know about tire expiration dates. An uninformed consumer thinks he or she purchased brand new tires when in reality those tires may have been sitting on the shelf for years. Even though the tires were never used on a vehicle, they are still several years old. Every tire has a birth date—the day it was manufactured—and an expiration date that is six years from that manufacture date. Most automobile manufacturers warn drivers to replace vehicle tires after six years. To wait any longer than that is a gamble with tire integrity and is risky for drivers.

So what can you, as a driver, do to protect yourself? When buying new tires, ask for the newest tires available, and look at the tire’s manufacture date. The manufacture date is a Department of Transportation (DOT) code of 10 or 11 characters embossed on the inside of the tire (see Figure 1). For new tires, the code is always 11 characters. However, tires manufactured before the year 2000 have a 10-character code. Expiration dates for tires manufactured before 2000 were based on a 10-year scale because the expected life-span of a tire was 10 years. Current guidance suggests that tires should be expected to last a maximum of only six years.

Tire Code Photo

Figure 1. A tire manufactured-date code, shown in the yellow box, may appear on the outside of some tires. The 11-character DOT code, shown in the red box, appears on the inside of tires.

Recently, some tire manufacturers have begun to stamp partial codes on the outside of tires (facing away from the vehicle) so that checking the date does not necessitate removing the wheel. This partial code, boxed in yellow  in Figure 1, is the most important piece of information about a tire. These last four digits of the DOT code represent the manufacture date of the tire. The last two digits refer to the year the tire was produced, and the first two digits identify the week number within that year. The tire shown in Figure 1 was manufactured on the 36th week of the year 2001. That tire was on a trailer that had been sitting in a field unused for 10 years, and it showed signs of dry-rot cracking. It is unclear whether trailer tires should be replaced every six years since they do not receive the same daily punishment as automobile tires. However, automobile tires should be replaced every six years.

The majority of people who take the gamble of keeping outdated tires do so to save money. Driving on outdated tires is risky not only for the driver of the car having those tires but also for other drivers. Take the initiative and change vehicle tires every six years, or sooner, to diffuse a potentially dangerous situation.


Authored by:
Matt Deskevich, Student Assistant at Penn State University – mdd5309@psu.edu
Reviewed by:
Bill Harshman, Penn State University (Has since retired)
Dennis Murphy, Penn State University (Has since retired)
Aaron M. Yoder, University of Nebraska aaron.yoder@unmc.edu
Kerri Ebert, Kansas State University kebert@ksu.edu


PTO-Driven Post-Hole Auger Safety

Post hole digger

(Source: Penn State University Ag Safety & Health)

Use the following format to cite this article:

PTO-driven post-hole auger safety. (2014) Farm and Ranch eXtension in Safety and Health (FReSH) Community of Practice. Retrieved from http://articles.extension.org/pages/70348/pto-driven-post-hole-auger-safety.


Post-hole augers driven by power take-offs (PTO) are mounted on a tractor and powered by the tractor’s PTO shaft. The transition from manual to mechanical power has reduced manual labor associated with post-hole digging but has increased the risk of injury when an operator does not follow safe operating procedures.

Prior to using any piece of equipment, read the operator’s manual. Follow all recommendations for operation, maintenance, and safety in the manual and on safety signage located on the auger. If you are unable to locate your operator’s manual, check with your local dealership or manufacturer for a replacement copy. Outlined below are safety recommendations to reduce your risk of an incident.

One-Person Operation

A post-hole auger is designed to be operated by one person. When the post-hole digger is in operation, the operator should be seated in the tractor seat. Other than the operator in the tractor seat, no one should be within 20 feet of the post-hole auger during operation. The tractor’s hydraulics should be used to position the auger for starting the hole and should never be manually set. Post-hole augers are equipped with a bar that rotates 90 degrees to enable the operator to remain in the tractor seat while positioning the auger. In the past, some post-hole auger owners would weld a bar to the rear of the machine for a second person to use to add downward pressure, however, this is an unsafe practice with a high risk for an entanglement incident, and this method should never be used

Personal Protective Equipment

The recommended personal protective equipment (PPE) when operating a post-hole auger includes close-fitting clothing, gloves, eye protection, hearing protection, and appropriate footwear, such as steel-toed boots. In regards to other clothing and hygiene, jewelry, scarves, or clothing with drawstrings should never be worn when operating a post-hole auger. Long hair should be kept securely tied above the shoulders.

Preoperation and Operation

Shields and guards must be in their proper place prior to operating a post-hole auger. New manufacturing standards include guards or shields for auger adapters, PTO drivelines, PTO universal joints, and connections. Depending on the make and model, check with the manufacturer to determine whether older post-hole augers can be retrofitted with updated shielding. Additional operation guidelines include the following:

  • Know the area and type of soil where you plan to dig.
  • Check the operator’s manual to determine the correct weight to place on the front of your tractor to balance the rear weight of the post-hole auger.
  • Remember to set the tractor’s brakes or put the tractor in park before you begin to dig.
  • Operate the auger at slow speed to achieve better performance and maintain more control.
  • Dig down several inches, and then lift the auger to release the soil. Repeat until the hole is the desired depth.
  • When the post-hole auger is not in use, make sure that the PTO on the tractor is shut off and that the auger is lowered to the ground.
  • When transporting a post-hole auger, fully raise the auger and watch for obstacles and obstructions that could hit the auger.

Freeing an Auger

If the auger becomes stuck (for example, due to contact with clay, rocks, or tree roots), promptly disengage the PTO and turn off the engine. With the power source is turned off, use a large wrench to slowly turn the auger backwards. After using the wrench, return to the tractor seat and raise the auger hydraulically.

Shear Pins

A shear pin is designed to break when too much pressure is placed on the drive, protecting the post-hole auger. Always use the recommended size and strength shear pin—substitutions may damage the machine and increase your risk of an entanglement incident. Keep a spare shear pin on hand to avoid downtime. Be sure to wear eye protection and gloves when removing a damaged shear pin.

Rocks and Other Obstructions

Post-hole augers have limitations. If a rock or other obstruction is preventing the auger from penetrating the ground, another location may need to be selected. If the selected location must be used, additional digging tools, such as a jackhammer or digging bar, might be needed to complete the hole.


Hydraulic fluid is stored at very high pressure and can penetrate a person’s skin or eye, causing serious injury or possibly death. Inspect your hydraulic lines for signs of wear and pinhole leaks without touching the lines with your hand. While wearing safety glasses, use a piece of cardboard or wood to pass over the suspected area. If a leak is located, relieve the pressure in the hydraulic system before repairing the leak.


Use the following format to cite this article:

PTO-driven post-hole auger safety. (2014) Farm and Ranch eXtension in Safety and Health (FReSH) Community of Practice. Retrieved from http://articles.extension.org/pages/70348/pto-driven-post-hole-auger-safety.




Implement for compact tractors: Selection, use, maintenance, and safety (2005) Louisiana State University AgCenter Reserach and Extension. Retrieved from http://www.lsuagcenter.com/nr/rdonlyres/1b522d98-ae78-4dfa-a258-7f845263….

Important safety message for owners/operators of post hole diggers. (n.d.) Farm Equipment Manufacturers Association. Retrieved from http://www.farmequip.org/media/file/PHDAD10.pdf.

Safety management for landscapers, grounds-care business and golf course. (2001) John Deere Publishing. Moline, IL.


Reviewed and Summarized by:
Linda M. Fetzer, Pennsylvania State University – lmf8@psu.edu
Dennis J. Murphy, Pennsylvania State University (Has since retired)
Michael Pate, Pennsylvania State University – mlp79@psu.edu
Robert A. Schultheis, University of Missouri – SchultheisR@missouri.edu
Aaron M. Yoder, University of Nebraska Medical Center – aaron.yoder@unmc.edu


A Guide to Teaching Safe Tractor Operation


Tractor Safety Driving Course
Tractor Safety Driving Course

(Source: Pennsylvania State University, Agricultural Safety and Health Program)

The Agricultural Safety and Health Program of the Department of Agricultural and Biological Engineering at the Pennsylvania State University has developed a manual called Organizing and Conducting a Safe Tractor Operation Workshop to assist agricultural producers, employers, and other experienced operators in organizing and conducting hands-on workshops that address safety practices for tractor operators. Hands-on tractor operation training is valuable because many new owners, operators, and workers are entering occupations such as production agriculture, agricultural services, forestry, landscaping, and golf-course maintenance that rely on agricultural tractors to complete tasks.

Fewer people grow up learning how to operate tractors and equipment, so the manual is useful for training individuals with varying levels of tractor-driving experience and ability. In addition to training people involved in production agriculture, the manual can also be used to train volunteers who mow places such as schools, churches, cemeteries, community parks, and grounds at civic centers.  The manual is a comprehensive guide that provides information about the following topics:

  • Choosing instructors, tractors, equipment, and driving courses
  • Driving and operating tractors and equipment safely
  • Conducting training workshops

The manual also includes performance evaluation forms.

For a copy, please email Linda Fetzer at lmf8@psu.edu.

Reviewed and Summarized by:

Glen Blahey, Canadian Agricultural Safety Association (has since retired)

Linda M. Fetzer, Pennsylvania State University  lmf8@psu.edu
Dennis J. Murphy, Pennsylvania State University (has since retired)
Michael Pate, Utah State University  michael.pate@usu.edu

NSTMOP: Program Overview



(Source: Pennsylvania State University – Ag Safety & Health Program)

The National Safe Tractor and Machinery Operation Program (NSTMOP) was developed through a collaborative effort involving Penn State University, Ohio State University, and the agricultural division of the National Safety Council. The project was funded by the U.S. Department of Agriculture, National Institute of Food and Agriculture. This program is now managed solely by Penn State.

The NSTMOP was originally developed and designed for 14- and 15-year-olds seeking employment in production agriculture. The U.S. Department of Labor’s Hazardous Occupations Order in Agriculture (AgHOs) regulation prohibits 14- and 15-year-olds from operating farm tractors and attached powered equipment unless the youths have successfully completed an approved safe tractor and machinery operation training program. For more information about these regulations, click HERE to visit the website of the U.S. Department of Labor.


In its third edition, this student manual provides in-depth information on what youth can expect when working on a farm, safety basics, agricultural hazards, how to operate a tractor, and how to handle materials, among other important topics. This latest edition features updated regulations, vibrant and detailed illustrations and photos, and an improved user-friendly layout, and includes:

  • An introduction to the NSTMOP
  • A program outline for the six modules
  • A driving test layout and evaluation form
  • A list of core competencies that each student should master
  • Instructional task sheets

While required for NSTMOP training courses, this manual is available to any adult or young person who wants to learn more about agricultural safety. To order the manual, visit Penn State Extension at https://extension.psu.edu/national-safe-tractor-and-machinery-operation-program-manual



Students must score a minimum of 70% on the written knowledge test and must successfully pass the skills and driving tests administered by the instructor.


Instructors use NSTMOP task sheets for the 24 hours of intensive classroom instruction. After students complete the classroom training and pass the 50-question knowledge test with a minimum score of 70%, they are permitted to take the skills and driving tests. After successfully completing both the classroom and driving components, students receive a formal certificate that allows them to work for hire in agriculture as 14- and 15-year-olds. Click HERE for more information about the NSTMOP and what is expected of students to complete the program and earn a formal certificate.


NSTMOP is administered nationally through the Cooperative Extension Service and agricultural education programs. To receive a listing of instructors from your state, send a request to nstmop@psu.edu. Click HERE for more information about becoming a NSTMOP instructor.

Reviewed and Summarized by:
Linda M. Fetzer, Pennsylvania State University – lmf8@psu.edu
Dennis J. Murphy, Pennsylvania State University – (has since retired)
Aaron M. Yoder, University of Nebraska Medical Center – aaron.yoder@unmc.edu

Tractor Operation for Hispanic Youth

Case-IH Disc Mower

Case-IH Disc Mower. Photo Source: Case-IH Media Library.

The Safe Tractor and Machinery Operation for Hispanic Youth program is a comprehensive program that provides culturally appropriate Spanish materials and video clips to teach some aspects of general farm safety and safe tractor and machinery operation to Hispanic youth. The video clips are only in Spanish, but the scripts, task sheets, and other instructional information are in English and Spanish.

The primary curriculum in this training program includes:

  • 26 task sheets from an older version of National Safe Tractor and Machinery Operation Program (NSTMOP) in Spanish and
  • 38 short video clips available to accompany nine of the task sheets; the clips range from 10 seconds to 2 minutes.

The program includes the Instructor Manual: Safe Tractor and Machinery Operation for Hispanic Youth and Task Sheets: Safe Tractor and Machinery Operation for Hispanic Youth. All task sheets include learning objectives, safety content, and suggested student activities. The manual groups the task sheets according to how they may be used.


The program includes three evaluation documents to gather feedback for the instructors on their programs. Included in the evaluation are the PreOp Test Evaluation Form and the Driving Test Evaluation Form that should be used when field testing the students. The third document evaluates the amount of material that the students learn in the program.


To view the complete curriculum, click on the PDF links below:

Instructor Manual

Task Sheets with Videos

  • Group 1 – Task Sheets 2.7, 2.9 and 2.10 – Spanish
  • Group 2 – Task Sheets 3.1, 3.2, 3.3, and 3.3.1 –   Spanish
  • Group 3 – Task Sheets 4.6, 4.6.1, 4.6.5, and 4.6.6 –  Spanish


Supplemental Task Sheets

  • Group 4 – Task Sheets 2.1, 2.3, 2.5, 2.5.3, 2.8, and 2.11 –  Spanish
  • Group 5 – Task Sheets 4.2, 4.2a, 4.2b, 4.2c, 4.3, 4.12, 4.13, and 4.14 –  Spanish
  • Group 6 – Task Sheets 5.1 and 5.4.1 – Spanish
  • Group 7 – Task Sheets 6.1 and 6.2 –  Spanish


This program was developed by the Pennsylvania State University, Department of Agricultural and Biological Engineering, Agricultural Safety and Health Program with funding support from the U.S. Department of Agriculture-National Institute of Food and Agriculture.

Reviewed and Summarized by:
Linda M. Fetzer, Pennsylvania State University – lmf8@psu.edu
Dennis J. Murphy, Pennsylvania State University (has since retired)
Aaron M. Yoder, University of Nebraska Medical Center – aaron.yoder@unmc.edu