Steel T-posts are the workhorse line post — but spacing and driving depth are where good fences and saggy ones part ways. Here is the field guide.
First, what T-posts are good for
Studded steel T-posts are line posts — they hold wire up between the anchors. They are not corner or brace posts. Every corner, end, and gate still needs a wood post and a proper H-brace; T-posts carry the run in between. Get that division right and the rest is detail.
Spacing: how far apart
| Fence type | Line-post spacing |
|---|---|
| Barbed / high-tensile, cattle | 16–30 ft (cattle tolerate wide spacing) |
| Barbed / high-tensile, general | 8–16 ft |
| Woven / fixed-knot wire | 8–12 ft |
| Hills, dips, corners, gateways | Tighter — close as needed |
Use battens or droppers between posts on wide-spaced high-tensile to keep the wires evenly spaced without the cost of more posts.
Driving depth: how deep
The rule: drive T-posts 18–24 inches into the ground — roughly a quarter to a third of the post length. The buried anchor plate (the wide fin near the bottom) is what resists pull-out, so it must be fully below grade. Go deeper in sandy or soft ground; a post that heaves or leans telegraphs slack down the whole fence.
Picking post length and weight
- Length: fence height plus 18–24 in. for the ground. A 48-in. fence wants roughly a 6.5–7 ft post.
- Weight per foot: heavier posts (about 1.25–1.33 lb/ft) are stiffer and straighten less under load — worth it on permanent perimeter; lighter posts are fine for temporary or low-tension lines.
Install details that matter
- Studs face the livestock side so wire pulls against the post, and clip wire to the studs so it cannot slide down.
- Drive them straight — a leaning line post looks bad and pulls the fence out of line.
- Use a real driver. A manual slam driver works; a powered post driver drives straighter, faster, and saves your shoulders on a big job.
- Cap them — uncapped T-posts are an injury hazard to livestock and people, especially around horses. Use safety caps.
When not to use a T-post
Skip steel T-posts for corners, ends, gates, and major dips or rises — those need wood posts and bracing to take the tension. And in deer country or where you want give, consider flexible fiberglass or composite line posts that bounce back instead of bending. Compare options in our line post options guide.
Frequently asked questions
How far apart should T-posts be?
8–16 ft for most fences (up to 30 ft for cattle on high-tensile), 8–12 ft for woven wire, and tighter on hills and corners.
How deep should a T-post be driven?
18–24 inches — about a quarter to a third of the post — with the anchor plate fully buried. Deeper in sandy soil.
Which way do the studs face?
Toward the livestock, so the wire pulls against the post and the studs keep it from sliding down.
Can I use T-posts for corners?
No — corners and ends need wood posts and an H-brace. T-posts are line posts only.
Bottom line
Space T-posts to the fence type, drive them 18–24 in. deep with the anchor buried and studs to the stock, brace your corners with wood, and cap the tops. Browse permanent posts and a post driver, and see the full perimeter fencing guide.
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