A good fillet knife is one of the most underrated pieces of fishing kit in Australia. Most anglers spend serious money on rods, reels, and lures — then fillet their catch with a supermarket knife that tears the flesh, loses a third of the fish to the bones, and rusts in the tackle box after three sessions.
The filleting knife is where the fish gets respected or wasted. Here's what to look for in one that does the job properly.
What makes a fillet knife good for Australian fishing?
Corrosion resistance — non-negotiable
Australian fishing puts knives in salt air, salt water, fish slime, and tackle boxes for months between thorough cleans. The steel needs to handle this without rusting at the blade, pitting at the spine, or seizing at the handle join.
14C28N Swedish steel is the right choice for Australian fishing conditions. The same steel used across the Koi Pocket Knife Aviary — chosen specifically because its 15% chromium content provides genuine stainless performance in coastal and marine environments. It handles the salt air of the Southern Ocean, the humidity of tropical north Queensland, and the neglect that happens when you're focused on fishing rather than equipment care.
Avoid knives that don't specify their steel. "Stainless" without a designation covers a huge range of quality — some of it entirely inappropriate for saltwater use.
Flexibility matched to the fish
This is where most anglers make their first mistake. Fillet knife flex isn't a preference — it's a specification that should match the fish you're targeting.
Flexible blades follow the contours of small to medium fish — running cleanly along the backbone, working around the rib cage, and skinning without tearing delicate flesh. The right choice for whiting, bream, small flathead, garfish, and other species under 2kg.
Semi-stiff blades have enough spine to handle the firmer flesh and larger frames of medium to large fish — snapper, flathead over 40cm, tailor, large bream — without the flex that becomes a liability on bigger species.
Semi-flex blades sit between these points — enough flexibility to follow a large backbone, enough spine to drive through denser flesh. The right choice for large pelagics: tuna, kingfish, large snapper.
Blade length matched to the fish
Too short and you're making multiple passes where one should do — losing flesh at every join. Too long and you lose control on smaller fish. The general rule:
- Small fish (under 40cm): 150–185mm blade
- Medium fish (40–70cm): 185–210mm blade
- Large fish (70cm+): 210–250mm blade
A handle that works wet
A fillet knife handle gets wet every session — fish water, sea water, blood. It needs to grip when wet without slipping, not absorb moisture or odour, and not swell or crack from repeated wetting and drying. G10 fibreglass composite is the right handle material for Australian fishing — it does all of this without requiring any care beyond a rinse.
Sharpness and edge retention
A fillet knife that isn't sharp wastes fish. The knife needs to be genuinely sharp out of the box and hold that edge through a session without needing constant touch-ups. 14C28N at 58 HRC achieves both — sharp enough for the precision cuts of filleting, hard enough to hold the edge through a reasonable session.
Our picks: the Koi Fish Fillet Collection
For small to medium fish — The King George Whiting ($235 AUD)
Named for one of Australia's finest eating fish — the King George Whiting, prized from Gulf St Vincent to Port Phillip Bay — this is the collection's precision blade. 185mm flexible fillet knife in 14C28N steel with G10 handle.
The flexible blade follows the contours of smaller fish without tearing — producing clean, even fillets from whiting, bream, flathead under 50cm, garfish, and any species where precision matters more than reach. The 58 HRC edge is sharp enough for the delicate flesh of a freshly caught whiting without the risk of a harder blade that chips on contact with small bones.
Best for: Whiting, bream, flathead, garfish, small to medium table fish Blade: 185mm | Flex: Flexible | Price: $235 AUD
→ Shop The King George Whiting
For the widest range of species — The Snapper ($265 AUD)
The Snapper is the collection's all-rounder — and for most Australian anglers, the right starting point. 200mm semi-stiff fillet knife named for one of Australia's most widely targeted species.
Semi-stiff flex sits in the sweet spot for the fish most Australians catch most often: snapper, medium flathead, tailor, bream over 35cm, whiting at the larger end, jewfish at the smaller end. Enough spine to drive cleanly through firmer flesh and larger frames; enough flex to follow the backbone without forcing a straight line through a curved fish. The 200mm blade gives you the reach for medium fish without losing control on smaller ones.
If you buy one fillet knife, buy the Snapper.
Best for: Snapper, medium flathead, tailor, bream, most common Australian species Blade: 200mm | Flex: Semi-stiff | Price: $265 AUD
For large pelagics and serious offshore fishing — The Blue Tuna ($295 AUD)
The Southern Bluefin Tuna runs in some of the most challenging fishing waters in the country — the Great Australian Bight, the offshore grounds south of Port Lincoln, the deep blue water of the Tasman Sea. It's a fish that demands serious equipment at every stage.
The Blue Tuna is the collection's large-fish blade — 225mm semi-flex fillet knife, the longest and most authoritative of the three. Semi-flex at this length gives you the ability to follow the backbone of a large fish while the extra reach means fewer passes and less wasted flesh on species over 70cm. The slightly heavier 2.24mm spine before grind gives it the authority that a longer blade needs on dense, meaty fish.
For yellowfin and bluefin tuna, large kingfish, large snapper, and any species where a shorter blade means you're working against the fish rather than with it.
Best for: Tuna, kingfish, large snapper, large pelagics Blade: 225mm | Flex: Semi-flex | Price: $295 AUD
The complete set — all three for $645 AUD
All three knives together save $150 against buying individually and give you the right blade for any Australian species. The complete set is the right choice for serious anglers who target a range of fish — or who want the right tool no matter what comes over the side.
How to sharpen a fillet knife
A dull fillet knife is the most common cause of wasted flesh and torn fillets. 14C28N sharpens easily and quickly:
Before a session: Three to five strokes per side on a ceramic rod at 15° restores a working edge. Thirty seconds.
Full sharpening: A whetstone at 1000 grit followed by 3000 grit, 15° per side. Do this every few months of regular use, or whenever the ceramic rod stops restoring a sharp edge efficiently.
What not to use: Pull-through sharpeners remove too much metal and change the angle. Electric sharpeners can overheat the edge. A whetstone and ceramic rod are the right tools.
Frequently asked questions
How do I know which fillet knife size to buy? Match the blade length and flex to the fish you target most. Small to medium table fish — King George Whiting. Most common Australian species — Snapper. Large pelagics — Blue Tuna. If in doubt, the Snapper handles the widest range.
Can I use a fillet knife for other kitchen tasks? A fillet knife is a specialist tool — its thin, flexible blade isn't suited to general kitchen work. Keep it for filleting and use a chef's knife for everything else.
How do I stop my fillet knife rusting? Rinse with fresh water after every session, dry completely before storing, and keep a light wipe of camellia or mineral oil on the blade for long-term storage. 14C28N is corrosion resistant, not corrosion proof — the fresh water rinse is the most important habit.
Browse the full Fish Fillet Collection →
Designed in Adelaide, South Australia. 14C28N Swedish steel. Ships via Australia Post.
