Are T Posts Galvanized? [Do They Rust?]

T posts also called steel posts, are generally galvanized to make them resistant to corrosion. In addition, they are strong and durable. These characteristics are the reason they are excellent for fence posts. However, can they rust? We consulted with the experts who furnished us with the following information.

T posts are galvanized to protect them from rust because they are exposed to the weather elements. However, they can still rust due to the following factors:

  • The thickness of the protective zinc coating
  • High humidity
  • Wet or soaked environments
  • Salt in the air or water
  • Acid rain

Despite steel being galvanized, it can rust. Keep reading as we unravel why this happens, how to maintain them, and how long they last. In addition, learn the pros and also the cons, if any.

A man builds a wooden fence with galvanized posts. Are T Posts Galvanized [Do They Rust]

Do Galvanized T Posts Rust?

Galvanizing steel involves immersing it in hot molten zinc which provides a coating resistant to corrosion. 

Steel is susceptible to oxidation resulting in rust. If you leave un-galvanized steel outside, it will react with the moisture to form rust. But, if you coat it with zinc, it provides a barrier that effectively blocks moisture from reaching your galvanized steel. This non-corrosive characteristic makes it last longer.

metal showing signs of wear and neglect

However, despite this amazing feature, it can still rust due to the following factors:

Thickness Of Zinc Coating

The average thickness of zinc coating is 85 microns, which is as thick as a sheet of A4 paper and can protect it for at least 100 years. Typically, the thicker your steel is, the thicker the zinc covering should be. 

The durability of the zinc coating on your steel post is dependent on its thickness. A thicker coating lasts longer than a thinner one. 

High Humidity

Metals rust when exposed to air and moisture. But, zinc will start rusting when the humidity levels are above 60%.

Wet Or Soaked Environments

Even though zinc can protect steel against moisture, it is not waterproof. When exposed to moisture, it will slowly corrode. 

If you live in an area that is frequently wet, it is likely to rust much faster, though, this is relative to the pH levels of the water. 

Zinc corrodes faster when the pH level is acidic or alkaline. On the other hand, the rate is lower when the pH is neutral. In addition, zinc becomes more corrosive in soft water than in hard water. Also, higher oxygen levels in the water will cause your zinc-coated steel post to rust faster.

Besides, water flowing at a high rate will cause more corrosion due to increased abrasion. 

Salt In The Air Or Water

The high levels of salt or chloride in the sea cause zinc to corrode at a very high rate. So, if you live in the coastal region, your galvanized steel fence post will experience this effect. 

Acid Rain

Sulfur dioxide pollution in the urban areas, when mixed with water and air, forms sulfuric acid, which then forms acid rain. Like other metals, zinc is affected by acid rain, even though it happens more slowly.  

Acid rain can also be formed when hydrogen sulfide is released into the atmosphere by features such as sulfur hot springs, volcanic gases, and sewage sludge. When hydrogen sulfide mixes with moisture, it forms acid rain.

What Materials Make T Posts?

These posts can be made from steel or rail steel. Steel is a mixture of iron and carbon, the latter being 2%. They are strong enough for putting up buildings and are also used to make fence posts. When steel rails are no longer needed for train tracks, they are turned into T posts for fencing.

Fence steel white boundary structure.

The Pros And Cons Of Galvanized T Posts

As mentioned, steel posts are galvanized to prevent them from rusting, so that they can last longer. This makes them suitable for fence posts because they can withstand even the harshest weather elements. It is one of the benefits of galvanized steel among several others.


This type of steel is becoming increasingly popular because of the undeniable advantages it has to offer, which include:


T posts may initially be costly. However, over time they are cost-effective because they need little maintenance, lasting many years without requiring too many repairs. 


First and foremost, steel does not rot or warp. Insects such as termites cannot attack it. Secondly, steel posts coated in zinc prevent them from rusting. 

It can last for at least 40-years and at least 25 years in the coastal areas. Furthermore, steel does not peel, chip, or crack and is non-combustible.

Easy To Maintain

After installing the posts, they will not need much maintenance because they don’t rust. They are strong, meaning they can hold up your fence much more firmly and for longer.   

Aesthetic Appeal

Steel posts have a sleek modern look, which improves the aesthetic appeal of your yard. It also increases the value of your home. 


There’s probably only one con with this type of fence post; they are expensive. Fence posts made of steel generally cost more than posts made from other materials such as wood, vinyl, concrete, aluminum, etc. Though they are cost-effective, the initial costs may not be favorable to some homeowners.

How To Maintain Your T Posts

T posts are easy to maintain. Since they are galvanized, they may stay for years without any maintenance. The zinc coating provides a covering that blocks moisture from reaching the steel. However, there is minimal maintenance you can do, including:

Reduce Risk Of Scratches

Scratching a T post causes the zinc coating to wear off, exposing the steel. If you don't do anything about it, it will start to corrode.

Paint The Posts

As explained earlier, in case of scratches appear, you can cover them by spraying paint suitable for use on galvanized steel.

Straighten Bent Posts

Straighten out any bent posts using the appropriate tools. It might be best to call a professional to do a quality job for you.

How Long Do T Posts Last?

Your steel post can have a long lifespan due to this splendid feature. It lasts between 34 and 170 years. 

Zinc is a metal that corrodes very slowly. It corrodes almost 100 times slower compared to other metals. The outer covering takes a long time to wear out before moisture can reach the steel post.

Since it requires very little maintenance, the only effort you need is to lessen the risk of scratches on your post. You can also touch up the areas exposed due to scratches. Using the appropriate color, spray paint like the one shown below that is suitable for galvanized steel. 

Have a look at this spray paint on Amazon

Lastly, your fence posts are unlikely to get damaged even in heavy rainstorms. Instead, they will possibly only bend and not fall to the ground. 

low fence, as protection against dogs. protects the playground from uninvited guests.

How Much Does It Cost To Install T Fence Posts?

Despite being cost-effective, a steel fence is much more expensive than other fence types. This is largely due to its strength and durability. 

A galvanized steel fence post costs between $30 and $60 per piece. Generally, the cost of a metal fence post ranges from $3 to $50, depending on the style, height, and shape, like the T posts. 

Prepare to spend between $15 and $110 for a manual hole-digger like the one shown below to dig holes for the posts.

Have a look at this hole-digger on Amazon. 

On the other hand, a powered hole-digger like the one shown below costs between $60 and $600. Alternatively, you could rent one that costs from $50 to $60 per day.

Have a look at this powered hole-digger on Amazon

The installation costs are less compared to hiring a professional to do the job for you. However, if you do not have the skills, do not attempt to carry out this project. You might experience challenges that would cause the costs to increase. So, in essence, it might be cheaper to hire an expert in this field. 

A professional contractor can save you a lot of money and time by advising you on the size of posts you need, the thickness, and even the quantity required. 

an elderly man with a drill builds metal fence. Are T Posts Galvanized [Do They Rust]

In Closing

T posts are dipped in molten zinc to provide a coating around them to protect them against rust. However, the initial costs can be high, though much more cost-effective in the long run.

Increasing in popularity; the pros far outweigh the cons, with durability being top on the list. It’s interesting to note, that they can last for as long as 100 years.

The costs of galvanized steel vary depending on various factors. As much as installing your fence and posts can be much cheaper, it is best to hire a professional. This is because they will advise you accordingly, helping you save your time and money.

We welcome you to read more of our posts. Do your steel fence posts need concrete? Find out more by clicking here: Do Metal Fence Posts Need Concrete

To align your steel posts straight, click here to learn more: How To Line Up Fence Posts Straight