Star Picket (Y Post) Installation: Depth, Spacing and Droppers

In Australia and New Zealand the standard steel fence post is the star picket, also sold as a Y post or star post. Drive intermediate posts 450–600 mm into firm ground, go deeper — 760 mm or more — at ends, corners and gates, and set the spacing by the fence rather than by the animal: about 3 m for stock netting, about 5 m for heavy or predator-rated stock fence, and up to 10 m for plain-wire runs provided droppers hold the wire spacing in between.

What is a star picket, and what do you call it on an order?

They are the same product: star picket, star post, steel fence post and Y post. Australian and New Zealand farms, hardware stores and fencing contractors say star picket; Y post is the manufacturing and catalogue term, because the rolled section is Y-shaped. On a purchase order, write “star picket” with the length, the section weight and the hole pattern — that combination is what gets quoted.

What lengths and grades should you order?

The AU/NZ catalogue range runs 1.35 m, 1.50 m, 1.65 m, 1.80 m, 2.10 m, 2.25 m and 2.40 m. On farms, 1.65 m and 1.80 m do most of the work: long enough to leave a useful height above ground after driving, short enough to handle by hand.

• Boundary and internal lines: the common 1.65–1.80 m post.
• Strainers, gates and high-impact positions: heavier sections and longer posts.
• Grade: we supply to the grade you specify — rail steel or structural steel to the grade specified on your drawing. Heavy-duty grades are available, and the weight per metre is confirmed per order.

Which coating standard applies to star pickets?

Standard	Applies to	Use it for
AS/NZS 4680	Hot-dip galvanised (zinc) coatings on fabricated ferrous articles	Star pickets, posts, rails and fabricated steel — the post standard
AS/NZS 4534	Zinc and zinc/aluminium-alloy coatings on steel wire	Wire and mesh products only — not posts

Quoting the wrong one is a common source of argument at inspection. Specify hot-dip galvanised to AS/NZS 4680 for the picket itself, and ask for the coating class and minimum coating mass to be confirmed against your local standard in the quotation — that is how we quote it, because coating classes differ between standards and between markets.

How deep do you drive a star picket?

• Intermediate posts: 450–600 mm into firm ground.
• Ends, corners, gate posts and strainers: 760 mm or more, and deeper in sand or soft ground.
• Reference points from published data: the GV Water farm fence design guideline puts timber main posts at a minimum of 1200 mm in the ground (with 660 mm for a secondary line) and specifies star posts of minimum 1650 mm length; AU manufacturer literature marks 460 mm in ground for a standard stockpost and 760 mm for the heavier XL section.
• Use the ground mark: the picket is manufactured with a ground mark on the section, so you can see when it has reached depth and keep the above-ground height consistent along the line.

How far apart should star pickets be?

Fence	Post spacing	Source
Stock netting / netting + top wire	About 3 m	GV Water farm fence design guideline
Heavy or predator-rated stock fence	About 5 m	AU manufacturer exclusion fencing data
Sheep and small stock, plain wire	Up to 10 m, with droppers between posts	WA DPIRD agronomy table (search summary only)
Cattle, 7-strand plain wire	Maximum 10 m, with droppers between posts	GV Water farm fence design guideline
US agricultural barbed-wire line	1 rod (16.5 ft / about 5.0 m)	USDA-NRCS Iowa CPS 382 — US practice, not AU

The familiar rule — “closer for sheep, wider for cattle” — is a direction, not a number. What actually sets spacing is the fence type: mesh holds its own wire spacing, so netting can be posted at 3 m, while a plain-wire fence needs droppers to earn its wider centres. On the DPIRD sheep and small-stock line specifically: that spacing comes from the DPIRD agronomy table, which we could only read as a search summary because the source PDF was not accessible, so treat it as an indicator and confirm with your local adviser.

What are droppers and when do you need them?

Droppers (also called stays) are short steel or timber posts clamped between two wires. They hold the wire spacing, stiffen the fence and take stock pressure, which is exactly how a wire fence earns wide post centres. The GV Water 7-strand cattle specification is the clearest published example: 7 strand wire with droppers equally spaced between posts, and a maximum of 10 m between posts.

The practical rule: on wire fences, add droppers rather than more posts. The right dropper spacing depends on the dropper you buy and the pressure on the line, so confirm it against the manufacturer’s table for that product rather than working from a rule of thumb.

How do you build ends, corners and gates?

• Go deeper and heavier. Ends, corners, gates and strainers are driven 760 mm or more, with published timber specifications going to 1200 mm minimum.
• Brace properly. The end assembly carries the tension of the whole run; under-built ends are the usual reason a good fence sags in its first year.
• Goat country: avoid external diagonal bracing posts, because goats use them as a ladder (Sustainability 17 (2025) 7295).
• Match the mesh to the post: post spacing and mesh aperture are chosen together. See field fence installation and fence height for sheep and cattle for the other half of the decision.

Holes, line markings and export notes

Star pickets are made with punched holes, defined hole spacings and line markings, and heavier farm sections add an extra hole below the ground mark so a barbed wire can be run at the correct height. Two things are worth pinning down on the order:

• Hole pattern and hole count. They differ between products and between market variants — the same 1.80 m length can be supplied with different hole counts for different destinations (Australian and New Zealand stock are commonly quoted at 14 versus 8 holes). State the pattern you want, or ask us for a drawing to approve.
• Section weight. Confirm the weight per metre against the grade you specified, because that is what carries the load in a strainer position.

Comparing profiles — plain, scalloped and studded — is covered in Y post profiles explained. Our full post range and hole drawings are on the star picket product page.

Frequently asked questions