The pipe for fence posts on a Texas wire fence should be at least Schedule 40 with a 2-3/8 in outside diameter. It should be painted or galvanized, and capped on top. That is the minimum in the USDA Natural Resources Conservation Service (NRCS) Texas fence specification, Conservation Practice 382. The same 2-3/8 in pipe is the minimum for the uprights and braces at corners, ends and gates. If you step up to 2-7/8 in pipe, you get a heavier post that NRCS lets you drive less deep in a brace. Used oilfield pipe is a different product, with its own Texas rules on radioactive scale.
What size pipe should you use for fence posts?
Use 2-3/8 in outside diameter (OD), Schedule 40 or heavier, for line posts on a Texas livestock wire fence. The NRCS Texas fence specification asks for “good quality, minimum Schedule 40” steel pipe for posts, painted or galvanized. You also need a permanent cap on each post to keep rain out. Corner, end and gate brace assemblies use the same 2-3/8 in minimum for both the uprights and the horizontal or diagonal members.
Bigger pipe than the 2-3/8 in minimum is up to you. When you weigh 2-3/8 vs 2-7/8 pipe, weight is the real difference: in Schedule 40, a 2-7/8 in post weighs about 60% more per foot. You buy, haul and set that weight on every post, so price both sizes for your whole run before you choose.
If horses will run along your fence, the 2021 NRCS Texas spec says to avoid barbed wire and T-posts where you can.
What do 2-3/8 and 2-7/8 mean on fence pipe?
Fence pipe sizes are trade names for the outside diameter, so “2-3/8” means a pipe 2.375 in across the outside. The table gives the actual OD, wall and weight for galvanized ASTM F1083 Schedule 40 fence pipe from the Wheatland Tube catalog sheet. It is the regular grade, with a 30,000 psi minimum yield.
| Fence-industry size | Actual OD (in) | Wall (in) | Weight (lb/ft) |
|---|---|---|---|
| 1-5/8 | 1.660 | 0.140 | 2.27 |
| 1-7/8 | 1.900 | 0.145 | 2.72 |
| 2-3/8 | 2.375 | 0.154 | 3.65 |
| 2-7/8 | 2.875 | 0.203 | 5.80 |
| 3-1/2 | 3.500 | 0.216 | 7.58 |
| 4 | 4.000 | 0.226 | 9.12 |
| 4-1/2 | 4.500 | 0.237 | 10.80 |
The names drift most at the small end: “1-5/8” fence pipe is really 1.660 in OD, and “1-7/8” is 1.900 in. Give the actual OD and wall when you ask for pricing, so nobody has to guess which naming you mean.
Fence makers also sell lighter-wall, higher-strength pipe. Wheatland’s WT-40 at 50,000 psi yield, for example, has a 0.130 in wall in 2-3/8 OD, which weighs 3.12 lb/ft. That pipe is lighter than Schedule 40. If your fence has to meet the NRCS spec, check that what you buy is Schedule 40 or heavier.
How deep and how long should pipe fence posts be?
Under the 2021 NRCS Texas fence specification, every post goes at least 3 ft into the ground. Sandy and wet soils need more depth. Each post also has to stand at least 2 in higher than the top wire. Say your four-wire barbed cattle fence has its top wire at 44 in. Each post then needs 36 + 44 + 2 = 82 in, so you would cut it at about 7 ft.
Braces you drive instead of burying have their own depths in the 2015 NRCS Texas spec. Driven 2-3/8 in brace pipe goes 5 ft deep. Driven 2-7/8 in to 4-1/2 in pipe goes 4 ft, and 5 in pipe and larger goes 3 ft. If you set posts in concrete, NRCS wants the top of the concrete belled and sloped so water runs off.
How far apart should pipe fence posts be?
Space line posts on a four-wire barbed cattle fence no more than 20 ft apart, or 30 ft apart if you add two or more stays between posts. Those limits come from Table 1 of the 2015 NRCS Texas fence specification. The same table covers other wire types:
| Fence type | Max spacing, no stays | Max spacing, with stays |
|---|---|---|
| Cattle or horses, 4 barbed wires | 20 ft | 30 ft |
| Smooth high-tensile, 12-1/2 gauge | 100 ft | 150 ft |
| Sheep, 7 barbed wires | 20 ft | 30 ft |
| Goats, 7 barbed wires | 15 ft | 20 ft |
| Woven net | 20 to 25 ft | not listed |
| Deer, 96 in woven | 20 ft | not listed |
Rough ground or heavy livestock pressure can call for closer posts on your fence. The 2021 edition of the spec has its own tables, so if your fence has to meet NRCS rules, confirm the current numbers with your local NRCS office.
Where do you need brace assemblies in a pipe fence?
You need a brace assembly wherever your fence starts, stops, or turns 20 degrees or more, under the 2021 NRCS Texas spec. On a long straight run over flat ground, the 2015 spec also keeps in-line pull assemblies no more than 1,320 ft apart, one spool of wire.
In steel, NRCS asks for welded brace assemblies with 2-3/8 in OD uprights and a 2-3/8 in horizontal brace about 6 ft long. Set the horizontal brace no lower than two-thirds of your top-wire height. NRCS allows a bolted clamp brace with approval, using 1/4 in A36 steel clamps galvanized to ASTM F626.
Texas A&M AgriLife Extension’s fencing cost estimator counts brace material like this:
- End brace: 2 posts and 1 brace
- H-brace: 2 posts and 1 brace
- 3-post corner: 3 posts and 2 braces
- 5-post corner: 5 posts and 4 braces
How many posts do you need for a quarter mile of fence?
You need about 63 line posts per quarter mile of four-wire barbed cattle fence at 20 ft spacing, on a straight run over flat ground. Add 4 brace posts and 2 brace pipes for an end brace at each end. With stays and 30 ft spacing, the same quarter mile takes about 41 line posts plus the same braces. The arithmetic uses the Texas A&M AgriLife formula: run length divided by spacing, plus one, less the posts used in braces.
| Line post spacing | Spaces in 1,320 ft | Line posts | Brace posts | Brace pipes |
|---|---|---|---|---|
| 20 ft, no stays | 66 | 63 | 4 | 2 |
| 30 ft, 2+ stays | 44 | 41 | 4 | 2 |
Each corner or gate on your fence adds a brace assembly from the AgriLife list. A quarter mile is exactly one spool length, so a straight run that long needs no in-line pull brace.
Weight matters when you plan the trip. A 7 ft post of 2-3/8 in Schedule 40 pipe at 3.65 lb/ft weighs about 25.6 lb. Your 63 line posts at 20 ft spacing come to about 1,610 lb before braces. In 2-7/8 in pipe at 5.80 lb/ft, a 7 ft post weighs about 40.6 lb.
What size pipe should you use for top rail?
No Texas or national standard sets a top rail size for a ranch pipe fence. The NRCS Texas spec sizes posts and braces only. It groups welded pipe fences with chain link, vinyl, panel and cable as fence types that cost more to install and maintain. NRCS says those fences are used mostly around corrals and homesteads, built to suit the animal you’re holding.
That leaves top rail to your judgment and your welder’s. The weights in the Wheatland table help you compare. A 1-5/8 in rail at 2.27 lb/ft is about 40% lighter per foot than 2-3/8 in pipe at 3.65 lb/ft. Ranchers on the TractorByNet forum describe pipe fences built with 2-7/8 in oilfield tubing for both posts and rails, and sucker rod as filler. That is builders’ practice from a forum, and no spec stands behind it. NRCS also gives no post spacing for rail-style pipe fence, so a builder who has done one near you is your best guide.
Should fence pipe be galvanized or painted?
Either one meets the NRCS Texas spec, which asks for steel pipe posts that are painted or galvanized and permanently capped. ASTM F1083 is the standard for galvanized welded fence pipe. It is zinc-coated inside and outside, sized from 1.315 to 8.625 in OD, and made in regular, intermediate and high-strength grades. It is meant as fence framework under ASTM F1043.
Black pipe needs paint before it goes in your fence line if you’re building to the NRCS spec. NRCS also wants every steel brace assembly welded and painted.
Is used drill pipe or oilfield tubing good for fence posts?
Used oilfield pipe can hold up a fence, but you are buying pipe that was made for downhole service. Nobody made it with fencing in mind. Tubing and casing are made to American Petroleum Institute spec API 5CT, drill pipe to API 5DP, and sucker rod to API 11B. None of those is a fence-pipe standard like ASTM F1083 or F1043. So used pipe won’t come with paperwork showing it meets a fence spec. The guide to mill certs explains what that paperwork proves when a job needs it. If you go the used route, you can get used oilfield pipe, drill pipe and sucker rod for fence from Winston Materials, on the same quote as new pipe.
What you can’t count on with used pipe:
- Wall and weight. Used pipe weight varies with grade and wear, so the Wheatland figures don’t apply. Measure the OD and wall of the lot you’re offered.
- Welding behavior. No published standard covers how used tubing or drill pipe welds in fence work. Ask your welder before you plan welded braces from it.
- Where it came from. One rancher on the TractorByNet forum calls pipe from sour (hydrogen sulfide) wells junk. Another describes sucker rod as soft and easy to bend. Those are forum opinions; no spec backs them.
- NRCS fit. The NRCS Texas spec asks for “good quality, minimum Schedule 40” pipe. If your fence is an NRCS job, ask your field office whether the used pipe you’re looking at qualifies.
What are the Texas rules on NORM in used oilfield pipe?
Used oilfield pipe can carry scale that holds naturally occurring radioactive material (NORM), and two Texas agencies have rules on it. The Railroad Commission of Texas covers oil and gas NORM equipment and waste. The Texas Department of State Health Services (DSHS) covers radiation limits and licensing.
- Tagging. Under 16 TAC 4.605, anyone who owns or operates oil and gas production equipment must tag NORM-contaminated pieces with the letters “NORM”.
- The exemption level. Under 25 TAC 289.259(d)(3), oil-production pipe with NORM scale is exempt if it reads 50 microroentgens per hour or less. That reading includes background, at any point you can reach. The survey meter has to read from 1 to at least 500 microroentgens per hour.
- Over the limit. Equipment over that exemption and the rule’s surface limits can’t be released for unrestricted use. Cleaning it requires a DSHS specific license.
- Surveys. The Railroad Commission’s NORM FAQ says neither rule specifically requires a survey, but tagging means someone has to find out. No specific license is needed to run a survey.
The Railroad Commission’s FAQ lists what can happen to NORM equipment: reuse for the same purpose, cleaning and then sale, scrap, a plugged well, or a licensed disposal company. It does not name fencing. The rules also don’t say who has to survey pipe before it is sold. On any used oilfield pipe you’re quoted, Winston’s included, ask for the lot’s NORM survey reading and whether any piece carries a NORM tag. The result you want is no tag and a reading of 50 microroentgens per hour or less, background included, at every point you can reach. That is the 25 TAC 289.259(d)(3) exemption level, and 16 TAC 4.605 is the rule that puts the tag on contaminated pieces. Pass on anything tagged NORM. For anything the rules leave open, DSHS and the Railroad Commission are the ones to ask.
Turning your fence plan into a pipe order
Your pipe order comes straight out of the numbers here: post count, cut length, OD and wall, plus braces. Write it as pieces, for example “63 pcs, 2-3/8 in OD Schedule 40, cut to 7 ft,” and list your braces the same way. Then work out how your posts come out of the lengths the pipe is sold in. The guide to saving on small metal orders shows how to nest a cut list so less ends up as drop.
With Winston Materials, you can put the whole fence on one quote: new or used line posts, brace pipe, and the tube or sheet for gates and pens. The steel pipe is sourced through a supplier network, cut to size, and delivered to your ranch or shop. If the delivery is headed down a caliche road, say where the gate is and whether a truck can turn around. Delivery is then spelled out on your quote.
A mill cert matters on a fence job when someone paying for it wants proof the new pipe meets its spec, such as Schedule 40 or ASTM F1083. Mill certs are available on request, so mark the lines that need one when you ask for the quote, before anything ships. Most quotes come back the same business day. The ag and ranch equipment page and the full materials list show what else can ride on the same order. When your cut list is ready, send it through the quote form.