Fencing crews running a skid steer loader alongside a tractor need one fact straight before spending money: the loader itself doesn't turn a post hole borer. This guide breaks down what actually drives an auger for skid steer setups, which auger diameter suits which post, and which Implements Direct post hole borer earns its keep fastest on a 2026 fencing job.
- Skid steers carry no PTO shaft, so a genuine auger for skid steer fencing work still runs off a tractor-mounted post hole borer.
- Sierra PTO Post Hole Borer Heavy Duty (NZ$1,395) spans 18-100HP tractors and swaps between 6 and 18 inch augers - buy for mixed fleets.
- Match auger diameter to the post spec first: 9 inch for standard fence posts, 18 inch for strainer and gate assemblies.
- Hydraulic downforce models cost more but pay off in clay and rocky ground where fixed-mount borers stall.
Why this matters
A lot of fencing quotes get built around "we've got a skid steer, we'll dig with that." That plan falls over the first time the auger needs rotational drive the loader can't supply. Getting the drivetrain right before the job starts saves a wasted trip back to the yard and a half-dug fence line sitting overnight in 2026's shoulder-season rain.
Most NZ fencing contractors and lifestyle block owners running a skid steer loader alongside a compact tractor solve this by digging with the tractor's 3-point linkage and PTO, then using the skid steer for spoil removal, post-driving and material shifting. Knowing that split up front changes what you actually shop for.
Who this is for
This guide is for fencing contractors and lifestyle block owners who already run or are about to buy a skid steer loader for post-driving, bucket work or spoil handling, and who need to sort out the drilling side of the job separately. If your tractor is 18HP to 100HP and you're setting anywhere from a dozen to several hundred posts a job, the buying logic below applies directly.
What to look for in an auger for skid steer loaders on fencing jobs
Drive type: PTO versus loader hydraulics
A skid steer's auxiliary hydraulics run buckets, grapples and rippers, but they don't deliver the sustained rotational torque a fishtail-lead auger needs to bore through clay and root mass. The post hole borers that actually get the job done on NZ fencing sites are PTO-driven, mounted on the tractor's 3-point linkage, not the skid steer's arms.
Auger diameter matched to the post spec
Standard 100-125mm round fence posts want a 9" auger; strainer, corner and gate assembly posts at 150mm-plus need an 18" head. Buying one size for the whole job means either an oversized hole packing loose around a light post, or a strainer post that won't seat.
Hydraulic downforce for hard ground
Fixed-mount borers rely on the tractor's 3-point linkage weight to push the auger down. In clay, shingle or rocky subsoil that's common across NZ paddocks, a hydraulic downforce unit keeps the auger biting instead of riding up and chattering at the surface.
Tractor HP and mounting compatibility
Check the borer's rated HP range against your tractor before ordering. A unit built for 18-40HP compact tractors won't take the torque load a 100HP unit is rated for, and running it outside spec strains the gearbox.
Auger points and replaceable teeth
The fishtail lead screw and bolt-on teeth are the wear parts. A borer that takes interchangeable auger heads with replaceable points means one gearbox drive unit services every hole size on the job instead of three separate machines.
Top picks for skid steer fleet fencing jobs
The mixed-fleet workhorse
The Sierra PTO Post Hole Borer Heavy Duty covers 18-100HP tractors at NZ$1,395 and takes interchangeable augers from 6" to 18" sold separately. It's the unit most fencing outfits running a tractor-plus-skid-steer combo buy first, because one gearbox drive covers every post size on the contract. Buy if your tractor sits anywhere in that HP band and you're setting mixed post sizes.
The hard-ground specialist
The Sierra PTO Post Hole Borer with Hydraulic Downforce runs NZ$2,595 and adds powered downforce instead of relying on linkage weight alone. It earns the extra spend on shingle, clay-pan or rocky ground where a fixed-mount unit stalls a foot into the hole. Buy for contractors quoting on known hard-ground sites; Skip it if your paddocks are soft loam and the standard borer already punches through clean.
The standard fence post pick
The Auger 9" for PTO Post Hole Borer at NZ$550 fits 100-125mm round posts, the diameter most batten and standard line-post runs call for. Buy as the first auger head in the kit — it's the one you'll use on the majority of holes across a 2026 fencing contract.
The strainer and gate post specialist
The Auger 18" for PTO Post Hole Digger at NZ$725 handles strainer, corner and gate assembly posts at 150mm-plus. Consider it only when the job spec calls for those larger posts; Skip the purchase if the contract is straight batten fencing with no strainers.
What to avoid
- Treating the skid steer as the drive unit. No skid steer on the market runs a PTO shaft strong enough for a fishtail auger — the borer mounts and drives off the tractor, full stop.
- Undersizing the auger for strainer posts. A 9" head won't seat a 150mm treated strainer post properly; you'll be back on site with the 18" auger and a half-set fence line.
- Skipping hydraulic downforce on known hard ground. A fixed-mount borer that rides up in clay or shingle costs more in stalled time than the downforce unit costs to buy.
Verdict comparison
| Pick | Drive & mount | HP range | Auger sizes | Price | Verdict |
|---|---|---|---|---|---|
| Sierra PTO Post Hole Borer Heavy Duty | PTO, 3-point linkage | 18-100HP | 6"-18" (sold separately) | NZ$1,395 | Buy |
| Sierra PTO Post Hole Borer Hydraulic Downforce | PTO, 3-point linkage, hydraulic downforce | 18-100HP | 6"-18" (sold separately) | NZ$2,595 | Buy for hard ground |
| Auger 9" | Bolt-on head, 50mm shaft | n/a | 9" | NZ$550 | Buy |
| Auger 18" | Bolt-on head, 50mm shaft | n/a | 18" | NZ$725 | Consider |
FAQ
What's the best auger for skid steer loaders on fencing jobs?
There isn't a true skid-steer-driven auger for fencing work, because skid steers don't run a PTO shaft. The practical setup is a PTO post hole borer like the Sierra Heavy Duty mounted on the accompanying tractor's 3-point linkage, with the skid steer handling spoil removal and post-driving.
Can a skid steer run a PTO post hole borer directly?
No. PTO post hole borers need a rotating PTO output, which skid steers don't have. They mount to a tractor's 3-point linkage and run off the tractor's PTO shaft.
What auger diameter do I need for strainer posts?
An 18 inch auger suits strainer, corner and gate assembly posts at 150mm and above. Standard 100-125mm line posts use a 9 inch auger instead.
How much does a PTO post hole borer cost in NZ in 2026?
The Sierra Heavy Duty unit runs NZ$1,395 without an auger, and the Hydraulic Downforce version runs NZ$2,595. Augers are sold separately, from NZ$550 for a 9 inch head to NZ$725 for an 18 inch head.
Is hydraulic downforce worth it on a post hole borer?
It's worth the extra cost on clay, shingle or rocky ground where a fixed-mount borer rides up instead of cutting. On soft loam paddocks the standard linkage-weight borer usually does the job without it.
What HP tractor do I need for a heavy duty post hole borer?
The Sierra PTO Post Hole Borer Heavy Duty is rated for 18-100HP tractors, though it's best suited to 35HP and up for sustained drilling in tougher ground.
Can I swap auger sizes on the same post hole borer?
Yes. The Sierra Heavy Duty borer takes interchangeable augers from 6 inch through 18 inch, so one gearbox drive unit covers every post size on a fencing contract.
One last thing
The fishtail lead screw and bolt-on teeth are the parts that wear out first, not the gearbox. Contractors running mixed post sizes in 2026 typically keep both a 9" and an 18" auger head in the ute and swap them on one Sierra borer, rather than buying two separate machines for one fencing contract.