Grain cart, chaser bin and mother bin turn up together in almost every piece of harvest research.
That’s where the confusion starts. North American machinery content uses grain cart for the machine Australian growers call a chaser bin. Add a mother bin and it’s hard to tell how many machines you’re looking at, let alone which ones your operation needs.
What most guides miss is that this is really a question about where your harvest loses time.
In this guide, we’ll explain what each machine does, how they differ and how they work together as a chain, so you can see whether you need one machine or both.
Grain Cart and Chaser Bin: The Same Machine, Different Names
Several Australian makers build chaser bins, and each comes from a different background. Here’s what each one documents publicly. Confirm current models with the maker before you buy.
GrainKing Nyrex
GrainKing started in 1962 as a family-run mechanical workshop and has made chaser, seed and super, and mother bins since 1981. The Nyrex chaser bin runs from 18 to 75 tonnes across single axle, tandem axle, tri axle and tri track configurations. Every Nyrex carries a five-year structural warranty. You can request a quote from GrainKing directly or buy through a dealer.
The range runs from 18 to 75 tonnes, or 23,000 to 94,000 litres. You can start with a smaller bin and move up a size later without changing the maker.
The Nyrex includes several features as standard: brakes, lights, a roll tarp, an electrically adjustable chute, and a three-camera kit. Tandem and tri-axle models feature independent hydraulic suspension alongside a hydraulically cushioned drawbar.
GrainKing designs and builds the Nyrex in Western Australia. That keeps the people who build your bin close to the people who supply its parts and service.
Coolamon
Coolamon builds its chaser bins at its workshop in Coolamon, NSW. The business started in 1972. Its chaser bin range lists six models, from the 24T20 to the 60T24, and it sells through more than 50 dealers.
Dunstan
Dunstan builds from its plant in Kerang, northern Victoria. It has worked in broadacre engineering for more than 50 years and makes chaser bins and mother bins. Its 60-tonne chaser bin has a 24-inch auger rated at 18 to 20 tonnes a minute.
Davimac
Davimac is a family-owned maker in Molong, in the NSW Central West, with more than 40 years in farm machinery. Its chaser bins run from 25 to 45 tonnes. The 45T, launched in July 2026, has a 24-inch auger rated at up to 18 tonnes a minute. Davimac sells through a nationwide dealer network.
Finch
Finch Engineering is a family-owned manufacturer based in Kaimkillenbun, Queensland. They build grain haulout bins, which fill the chaser bin role, along with mother bins and augers. Finch also runs a mobile field service team that services its bins nationwide.
What to Compare When Choosing a Chaser Bin Manufacturer
Whichever maker you’re looking at, the same checks apply. Ask for the answers in writing, and ask what’s standard and what’s an extra, because inclusions vary from bin to bin.
Capacity Range and Axle Configurations
Having a full capacity range is critical as your farming operations expand. Choosing a manufacturer with a limited range restricts your options when adding or upgrading harvesters
Axle choice follows your paddocks:
- Single axle. Lighter and narrower. Suits smaller operations, firm ground and tight paddock layouts.
- Tandem axle. Spreads the load over more tyres. Handles wetter ground and heavier capacities.
- Tri-axle and tri-track. Built for high-capacity operations and controlled traffic farms.
Auger System and Unload Speed
Unload speed is the number you’ll feel at harvest. Check the auger diameter, the drive type and the discharge. The bins above run 22-inch to 24-inch augers. The drive is PTO, hydraulic or a combination, and a pivoting discharge lets you position the spout over a truck without moving the bin.
Ask which drive a quoted unload rate applies to. GrainKing’s own Support FAQ shows why: the same bin unloads faster on full PTO than on a hydraulic/PTO drive. Ask how the drive is built too. Belt-and-chain systems have more parts to maintain than a gearbox.
Warranty, Build Quality and Parts Support
A structural warranty shows how much a maker trusts its build. Ask what it covers, how long it runs and what it excludes, so you can compare like with like.
Parts decide how long a breakdown lasts. A maker that builds in Australia usually has a shorter parts chain than one relying on imported components. Ask where parts ship from, how quickly they reach you in harvest and who services the bin. Find out whether you buy direct or through a dealer.
How the GrainKing Nyrex Compares
Here’s how the Nyrex measures up against the same checks.
Capacity and axles. The range runs from 18 to 75 tonnes, or 23,000 to 94,000 litres, so you can move up a size without changing maker.
Auger and unload rate. The 18T to 38T models have a 22-inch pivoting discharge auger, and the 45T to 75T models have a 24-inch auger. The Support FAQ gives unload rates of up to 16 tonnes a minute on hydraulic/PTO and up to 20 on full PTO for the smaller models. The larger models reach up to 18 and up to 25. The full PTO option drives the auger through a gearbox, so there are no belts or chains to maintain.
Build and inclusions. Tandem and tri-axle models have independent hydraulic suspension with 400 mm of travel, and the drawbar is hydraulically cushioned. Brakes, lights, a roll tarp, an electric adjustable chute and a three-camera kit are standard.
Warranty and support. Every Nyrex carries a five-year structural warranty. GrainKing is based in Western Australia, with sites at Canning Vale and Cunderdin and at Drayton in Queensland. The Nyrex was also a finalist for the 2018 Swedish Steel Prize.
Explore the Nyrex Chaser Bin Range
Matching the Bin to Your Operation
Start with your header. The bin has to take grain as fast as the header delivers it, then empty it into a truck or mother bin before the header’s tank fills again. A header and chaser cost around $500 to $800 an hour to run, cutting or waiting, so a bin that’s too small or too slow costs you cutting hours.
Then look at your paddocks. Soft ground and controlled traffic farming point to tandem, tri-axle or tri-track. Firm ground and tight layouts can suit a single axle.
Hydraulic and in-cab features matter when one person runs the job. Cameras, an electric chute and a cushioned drawbar make loading a truck a single-operator task.
Check local transport regulations before purchasing. Higher-capacity Nyrex models measure 4.5 metres wide, so overall width and loaded weight dictate road transport permissions under state regulations.
Tell us your header, tractor and paddock setup and we’ll match the size. Request a quote.
Frequently Asked Questions About Choosing a Chaser Bin
Who are the main chaser bin manufacturers in Australia?
GrainKing, Coolamon, Dunstan, Davimac and Finch are the names buyers meet most. They differ in capacity range, axle configurations and how they sell, through dealers, direct or both. Among the makers documented above, GrainKing’s Nyrex has the broadest range, from 18 to 75 tonnes, with a five-year structural warranty.
What is the best chaser bin in Australia?
It depends on your header capacity, soil type and paddock layout. Compare makers on capacity range, axle options, auger and unload rate, warranty and support. The GrainKing Nyrex is a strong choice across those checks, particularly if you need a full range from 18 to 75 tonnes.
What makes a chaser bin Australian-made rather than imported?
The difference is where the steel is sourced and fabricated and who engineers the bin for Australian soils and crops. That shapes parts availability and how close support is in harvest. GrainKing designs and builds its Nyrex bins in Western Australia.
What is the difference between a single-axle and tandem-axle chaser bin?
A single axle bin is lighter and narrower. It suits smaller operations, firmer ground and tight paddock layouts. A tandem axle bin spreads the load over more tyres, so it handles wetter ground and heavier capacities. Your soil type, header capacity and paddock conditions decide the right choice. The Nyrex comes in both.
What warranty does GrainKing offer on its chaser bins?
Every Nyrex configuration comes with a five-year structural warranty. A structural warranty shows a maker’s confidence in the frame and body. Ask any maker what theirs covers, how long it runs and what it excludes, so you can compare like with like.
Choose a Chaser Bin That Keeps Your Header Cutting
A chaser bin is only as good as its fit with your header, your paddocks and the support behind it mid-harvest.
Capacity, axle type, unload rate, warranty and parts all matter when a bin is expected to work through ten or more harvests.
GrainKing Nyrex chaser bins are built in Western Australia in sizes from 18 to 75 tonnes. You can choose single axle, tandem axle, tri axle or tri track, and every Nyrex carries a five-year structural warranty.
View the GrainKing Nyrex Chaser Bin range or request a quote from the GrainKing team.
