The best Filling knives, compared.
Top pick: Axus Decor Pro-Fill Best value: Axus Decor Pro-Fill – Best value as the handled flexible knife at about £5.39, 4.7 from 1,393 reviews, if you measure the blade against the 2 inch title. Updated October 2026.
The title and the dimensions row do not agree. A filling knife is the flat, flexible blade you use to press filler into cracks and holes and leave the repair level. Toolstation and separate them: the filling knife is thinner and bendier; a stripping knife lifts wallpaper or paint. That split is on the [filling knife or stripping knife](/hub/painting-supplies/filling-knife/sub/filling-knife-or-stripping-knife) page. Harris reviews say the bare edge cuts fingers. A putty knife on amazon.co.uk can be either, because these listings sit in. Do not buy one title that promises both jobs and then use a floppy blade as a chisel.
The title and the dimensions row do not agree. A filling knife is the flat, flexible blade you use to press filler into cracks and holes and leave the repair level.
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Personal buying guide
Question 1 of 2
Which grip do you want?
The Axus Decor Pro-Fill is £5.39 on amazon.co.uk as a single flexible filling knife with a rubber handle and a hanging hole, model AXU/FKB2. The title says 2 inch / 50 mm, while the dimensions row prints 53 cm by 7 cm and reviews also call the blade 4 inch or, in one title, 25 mm, so the width you receive is something you should measure rather than trust from the stars alone. The star line is 4.7 from 1,393 reviews, high on count, but that figure can pool sizes on amazon.co.uk. Reviews that mention rust say the blade did not rust; one edge defect is reported. The listing describes an ultra-flexible stainless blade for gaps on walls, ceilings, and wood. Across this set it is the best value when you want the handled Pro-Fill shape for one width and you have checked the blade against the 2 inch title.
Pros
Cons
Best for: You want one rubber-grip flexible knife for screw holes and you will measure the blade after it arrives.
Less suitable: You need several widths in one box, or you will buy from the title alone without measuring.
Specifications
Common questions
What width does this Axus listing state?
The title says 2 inch / 50 mm, model AXU/FKB2. The dimensions row says 53 cm by 7 cm. Reviews also call it a 4 inch knife and, in one title, 25 mm. Do not rewrite the title as 4 inch.
What does the listing say about rust?
It says stainless steel and an anti-rust blade. Reviews that mention rust say the blade did not rust. That is not a promise that every blade stays bright if you store it wet.
Is this a set?
No. The box line is one filling knife. The listing names a rubber handle and a hanging hole.
The ROLLINGDOG set is £25.99 on amazon.co.uk, model 50361, with four beech-handled blades stated at 1, 2, 3 and 4 inch and a bullet line of 420 stainless steel and a full tang. The title also says wallpaper scrapers, and the bullets name scraping, cleaning, wall repairs, spreading filler, and removing caulk and joint compound, so the listing is asking you to treat one shape as two jobs. The star line is 4.7 from 469 reviews, a shorter sample than Harris or Axus. UK-facing complaints in the reviews include sticker residue, a 2 inch blade that snapped on nail holes under light pressure, another blade that failed after about five months, and one handle that arrived loose. Some reviewers say the blades feel stiffer than they wanted for filling. It is the wood-handle option in this set only if you accept that title mix and those failure notes.
Pros
Cons
Best for: You want beech handles and numbered 1 to 4 inch blades and you accept the scraper title on the packet.
Less suitable: You need a very floppy filling blade, you cannot risk a snap on nail holes, or you want a sub-£10 pack.
Specifications
Common questions
What is in the ROLLINGDOG set?
The bullets say four knives: 1 inch, 2 inch, 3 inch, and 4 inch, with beech handles. The steel line says 420 stainless steel and a full tang. Model 50361.
Is this only a filling knife?
The title also says wallpaper scrapers. The bullets name scraping, cleaning, wall repairs, spreading, and removing caulk and joint compound. Wallpaper hanging is not spelled out as a method.
What failures show up in the reviews?
Stickers that leave residue come up more than once. One review says the 2 inch blade snapped under light pressure on nail holes. Another blade snapped after about five months. One handle arrived loose and could not be tightened.
The Harris Seriously Good continental pack is £5.04 on amazon.co.uk and puts four flexible stainless blades in your hand at 2, 3, 4 and 5 inch, model 102064328. The star line is 4.6 from 3,982 reviews, the largest sample in this comparison, and UK comments describe screw holes, skirting gaps, and wood filler as well as the cuts the edges can give. Several of those UK reviews say the bare steel cuts fingers, and one returned pack had a burr on every knife and a bent corner on the second-smallest blade. Aftercare on the listing and on harrisbrushes.com is warm soapy water, then dry completely before storing. The material line can show wood beside TPR; this comparison treats the grip as rubber (TPR). Across this set it is the top pick when you want every width printed on the box and you will treat the edges as sharp, not as a handled first knife.
Pros
Cons
Best for: You are filling a room of small holes and cracks and want four printed widths in one cheap pack.
Less suitable: You want one rubber-handled knife, you dislike bare sharp edges, or a burr-on-return story puts you off.
Specifications
Common questions
Which sizes are in the Harris pack?
The box line lists a 2 inch, a 3 inch, a 4 inch, and a 5 inch filling knife. Model number 102064328.
How does the listing say to clean them?
Clean with warm soapy water and dry completely before storing. One review says they wipe clean and do not rust.
What do the UK reviews say about the edges?
Several UK reviews say the edges are sharp enough to cut fingers. One returned pack had a burr on one side of every knife and a bent corner on the second-smallest blade.
The ZAVIA continental pack is £3.99 on amazon.co.uk, the lowest shelf price in this comparison, with four flexible blades and plastic grips and no storage case in the box line. The listing says stainless steel and four different widths, but inch or millimetre sizes are not printed, so you cannot match a blade to a hole before you open the pack. The star line is 4.1 from 40 reviews, and only eleven UK reviews are recorded for this listing. Two of those eleven say the blades rusted after water and are not stainless; three mention finger cuts from sharp edges, and one reports two deep cuts. That is a thin UK sample against a steel claim the reviews dispute. It suits only a disposable brief where £3.99 matters more than numbered widths or a stainless line this review sample does not support.
Pros
Cons
Best for: You want the cheapest four-blade pack for a one-off job and you will dry every blade after washing.
Less suitable: You need printed widths, a rubber or wood handle, or a stainless claim backed by this review sample.
Specifications
Common questions
Are the blade widths printed?
The title says a pack of four and the bullets say four sizes, from narrow gaps to wider areas. Inch or millimetre sizes are not printed on the listing.
Does it include a storage case?
No. The included-components line is four continental filling knives with plastic grips. A storage case is not in that line.
Do the reviews support the stainless claim?
The listing says stainless steel. Two of the 11 UK reviews say the blades rusted after water and are not stainless. Three of those 11 say the edges cut fingers.
Four amazon.co.uk listings were scored from 0 to 100. Amazon evidence is 30, fit for filling is 25, review outcome is 25, and value is 20. A star average is not a width test, and a stainless line is not scored as rust-proof when reviews on that listing say the blade rusted. A pooled rating is not treated as proof of one size. This is not a laboratory test. The top pick is the highest score, once. Best value is the handled flexible knife at £5.39 whose title states a width, once, with the width conflict left in view.
Amazon evidence
30%Star rating and review count on amazon.co.uk. A large count still loses points when reviews describe another width, because amazon.co.uk can pool sizes on one listing.
Fit for filling
25%A flexible blade for filler, widths you can name, and a handle if the edge is bare. A title that also says wallpaper scraper scores down. Unnumbered widths score down.
Review outcome
25%UK comments that report finger cuts, a burr, a snapped blade, sticker residue, or rust after washing. Silence, or a short sample, scores lower than a large file that still names the fault.
Value
20%Shelf price in GBP against a form you can compare. £3.99 does not outrank printed widths when the steel claim is disputed. £25.99 does not win on handles alone.
Buy the blade for the job, the printed width, and a steel claim the reviews do not contradict. Four amazon.co.uk listings were scored from the comparison files. A flexible filling knife presses filler. A stiffer stripping knife lifts paper or paint. Width, handle, and the conflicts on each listing are set out in the [filling knife buying guide](/hub/painting-supplies/filling-knife/sub/filling-knife-buying-guide). The top pick and the best value are named from those scores.
A filling knife is the flat, flexible blade UK decorators use to press filler into cracks and holes and to leave the repair level. A stripping knife is thicker and is meant to lift wallpaper or paint. A putty knife on amazon.co.uk can be either, because these listings sit in Putty Knives. Toolstation and ProDec draw the line by flex: the filling knife is the thinner, bendier blade. Do not buy one title that promises both jobs and then use a floppy blade as a chisel.
A filling knife is the thinner, bendier blade. A stripping knife is thicker and lifts wallpaper or paint. A title that promises both is a conflict, not two tools.
The Axus title says 2 inch / 50 mm. The dimensions row says 53 cm by 7 cm, and some reviews say 4 inch. Measure the blade. Do not rewrite the title as 4 inch.
Stainless on the listing is not rust-proof. Harris aftercare is warm soapy water, then dry completely. Two ZAVIA reviews say a wash left rust.
Fit for filling is 25 of the 100 points. Start with a flexible blade for filler. A stiffer knife is for lifting paper or paint, and the ROLLINGDOG title also says wallpaper scrapers, which is a mixed job. UK sizes in the sources run 2 inch (50 mm), 3 inch (75 mm), 4 inch (100 mm), and 5 inch (125 mm) on the Harris pack. Narrow blades suit holes and corners. Wider blades feather a patch. ZAVIA says four sizes and prints neither inches nor millimetres.
Review outcome is 25 of the 100 points, and it is where a stainless sentence meets the comments. All four listings say stainless. Axus reviews that mention rust say the blade did not. Two of eleven ZAVIA UK reviews say the blades rusted after water and are not stainless. Dry every blade. Harris aftercare is warm soapy water, then dry completely before storing. The Harris Ultimate 2 inch is a different product, high-carbon steel, so that steel line does not transfer to pack 102064328.
Three typical situations, each with a recommendation from this comparison.
You want one handled knife and a width you can check. The Axus Decor Pro-Fill at about £5.39 has a rubber handle and a hanging hole, and 4.7 from 1,393 reviews. The title says 2 inch / 50 mm. The dimensions row does not agree, so measure the blade.
You want four widths in one cheap pack and you will treat continental edges as sharp. The Harris Seriously Good pack at about £5.04 lists 2, 3, 4 and 5 inch, with 4.6 from 3,982 reviews. Several UK reviews say the bare steel cuts fingers.
You already own a stiffer stripping knife and only need a flexible filling blade. The Harris pack is the flexible set with printed widths. On older buildings, follow HSE lead and dust guidance: leave sound paint, and do not dry-sand or burn it.
The top pick is the Harris Seriously Good continental pack at about £5.04. It is the highest score: four printed widths from 2 to 5 inch, flexible stainless blades, and 4.6 from 3,982 amazon.co.uk reviews. UK reviews also say the edges cut fingers, and one returned pack had a burr and a bent corner. The best value is the Axus Decor Pro-Fill at about £5.39: one rubber-handled flexible knife, 4.7 from 1,393 reviews, and a title that says 2 inch / 50 mm. The dimensions row and some reviews disagree, so measure the blade. Neither score is a laboratory test. Stainless on the listing is not a promise that a wet blade stays bright.
Axus Decor Pro-Fill
Best value as the handled flexible knife at about £5.39, 4.7 from 1,393 reviews, if you measure the blade against the 2 inch title.
Editorial
Peter F. is the editor for DIY & tools at productscompared.co.uk. Comparisons in this category are checked against amazon.co.uk listings, review evidence and public UK sources.
Guides on what to look for, how to use a product, and common mistakes.
Public UK sources used for this comparison. Listing prices, stars and review counts are the amazon.co.uk figures saved for these four ASINs. The Harris price was also noted by Morris and Mica on 17 October 2026.
This page contains affiliate links to amazon.co.uk. If you buy through them, we may earn a commission at no extra cost to you. Prices, stars and review counts are the UK listing lines in this comparison. Morris and Mica noted the Harris pack at £5.04 on 17 October 2026. We did not run a lab test.
