The best threadlockers, compared.
Top pick: Bäder B270Eco high green, 10 ml Best value: kintsukuroi medium blue, 50 ml – About £8.88 for a stated 50 ml of medium blue, about £0.18 per millilitre, with the cap complaints kept in the judgement. Updated October 2026.
It cures to a hard plastic when air is shut out between close-fitting metal threads, so a fastener is less likely to walk loose under vibration. Medium, often blue, is for a joint you will undo with hand tools. High strength is for a joint that should stay: green on UK scale, red on many own-brand pairs. Low strength, often purple, is for small screws and for aluminium or brass at modest loads. A usable listing names one strength, a matching colour and a millilitre figure. A leaked cap or a rubbed-off date belongs in the judgement. A or name on another brand is the seller's label. The [buying guide](/hub/diy-supplies/threadlocker/sub/threadlocker-buying-guide) covers strength, colour codes, fill and the metal-only limit. Scores use the star line and the number of ratings behind it, whether the listing agrees with itself, the price against a fill you can read, and comments on leaks, dates and caps.
It cures to a hard plastic when air is shut out between close-fitting metal threads, so a fastener is less likely to walk loose under vibration. Medium, often blue, is for a joint you will undo with hand tools.
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Personal buying guide
Question 1 of 2
Will you undo this fastener later?
This 10 ml Bäder bottle is titled high-strength green, at £5.45, with 4.8 from 271 ratings, the highest star line in the set that still has a few hundred reviews. The upper-temperature cell says 180 °C, and a bullet mentions slightly oily screws. UK reviews say a little is enough and that heat is needed to loosen the joint. The listing does not print a removal temperature. The form cell says paste, while other Bäder listings in this set say liquid, and the rank cell is Sewing Thread. The page asks about aluminium and does not answer; compatible material says metal. B270Eco is the seller's name, not a Loctite certificate.
Pros
Cons
Best for: A metal thread you intend to leave, if you or a workshop can heat it later.
Less suitable: A fairing bolt, a bike bolt, or any fastener you expect to undo with a spanner on a cold joint.
Specifications
Common questions
How do buyers say they undo it?
UK reviews say a little is enough and that heat is needed to loosen a high-strength joint. The listing does not print a removal temperature.
What form does the cell give?
The item-form cell says paste. Other Bäder listings in this set say liquid. The container cell says bottle.
Does the listing answer the aluminium question?
The page asks whether it works on aluminium. There is no yes or no in the cells. Compatible material says metal.
The title says 50 ml medium blue at £7.99, and the rating line is 4.8 from 22, with five UK review texts on the listing. That count is too small to weigh like the listings with hundreds of ratings. A bullet says initial curing in 20 minutes and full strength in 24 hours, on clean, dry metal threads only, and it says not to return unused liquid to the bottle. It also says the bottle is half filled on purpose. The dimensions cell is 1 × 1 × 1 cm at 90 g, which is not a plausible bottle, and there is no colour cell and no volume cell. The page does not say the liquid is food safe.
Pros
Cons
Best for: A later look only if the live page shows a real 50 ml bottle and more reviews than these 22.
Less suitable: A first buy decided on the 4.8 alone, or any plastic or food container.
Specifications
Common questions
Does the listing allow plastic or food containers?
The page asks both. The safe-use bullet says only use it on metal threads, and it says to avoid skin and eyes. It does not say the liquid is food safe.
What cure times does the bullet give?
Initial curing in 20 minutes and full strength in 24 hours. Threads should be clean and dry. Do not return unused liquid to the bottle.
How many reviews support the 4.8 score?
The customer-reviews line says 4.8 from 22 ratings. Five UK review texts are on the listing. That is a small count beside listings with hundreds of ratings.
Nanoxa sells a medium blue bottle and a high-strength red bottle, 50 ml each, at £12.99, with 4.7 from 528 ratings. The bullet says the blue comes off with hand tools and the red needs heat, with an initial set in 20 minutes and full strength in 24 hours. It does not give a heat temperature or a service-temperature figure. Each bottle is described as 100 ml capacity holding 50 ml, so air remains and the anaerobic liquid does not harden in the bottle. A UK review says the blue bottle kept opening and pouring, and that liquid got on skin. At £12.99 this is the highest shelf price in the set. The material cell says plastic.
Pros
Cons
Best for: You know you need both a hand-tool grade and a heat grade, and you will check the caps on arrival.
Less suitable: One first bottle for a bolt you will undo, and anyone who does not want liquid loose in the bag.
Specifications
Common questions
How does the listing say you remove each colour?
The bullet says the medium blue comes off with basic hand tools and the high-strength red needs heat. It does not give a heat temperature.
Why are the bottles not full?
The bullet says each bottle has a 100 ml capacity and contains 50 ml, so air remains and the anaerobic liquid does not harden in the bottle.
What leak complaint is in the UK reviews?
A reviewer says the blue bottle kept opening and pouring, and that liquid got on their skin. Another short review says not to buy, without more detail.
This 10 ml Bäder bottle is medium strength, the colour cell is blue, and the shelf price is £5.39, with 4.7 from 229 amazon.co.uk ratings. A bullet states −55 °C to +180 °C and says it secures slightly dirty and oily screws. UK reviews say the lock holds and that buyers could still undo the screws. The seller name B243Eco is not a Loctite 243 certificate, even where reviews compare the idea with Loctite. Country of origin is Germany and the weight is 18 g. The listing does not print a cure time. A non-hazardous line is a seller bullet, not an independent safety test.
Pros
Cons
Best for: A metal fastener you will undo with hand tools, when you want a small medium-strength blue bottle with a few hundred reviews.
Less suitable: A joint you intend to leave in place, and anyone who needs the bottle to be Loctite 243.
Specifications
Common questions
Is this Loctite 243?
The listing name is Bäder B243Eco. The listing does not say the bottle is Loctite 243. UK reviews compare the idea with Loctite, which is not a certificate.
What temperature does the listing state?
A bullet says -55 °C to +180 °C. There is no separate upper-temperature cell on this ASIN.
Does the listing claim oily threads?
Yes. A bullet says it secures slightly dirty and oily screws. The question line also asks about oily surfaces.
Across 5,126 amazon.co.uk ratings at 4.6, reviewers use this Henkel tube on car and bike bolts, which is the largest review count in the set. The shelf price is £6.60. The volume cell says 5 millilitres, the title says 1 x 5 g, and UK reviews say there is very little in the tube. The colour cell is transparent and the included line says Normal, so there is no blue, red, or green dye to match a strength chart. Compatible material is metal, and the listing does not answer the plastic question. Watch-link reviews say the lock did not hold. The rank cell also lists Car Exhaust Seals, which is a catalogue oddity rather than a use you should copy.
Pros
Cons
Best for: You want the Loctite name on a small metal bolt and you accept a 5 ml tube that does not state a colour grade.
Less suitable: A joint you need to match to blue, red, or green, and a job that will use more than a few drops.
Specifications
Common questions
Does this listing say it works on plastic?
The page asks whether it can be used on plastic. The compatible-material cell says metal. The listing does not answer yes.
How much is in the pack?
The volume cell says 5 millilitres. The title says 1 x 5 g. The included-components line says Loctite Threadlocker Normal 5 ml. UK reviews say there is very little in the tube.
What strength colour does the listing give?
The colour cell says transparent. Special features say fluorescent and transparent. The included line says Normal. No blue, red, or green grade is printed.
The title says blue and red, medium and high, at £3.99, with 4.6 from 381 ratings. The colour cell says Blue (MID-Strength) only, and there is no millilitre figure. Weight is 10 g, the package is 7.9 × 7.6 × 1.9 cm, and the manufacturer cell is XJYEU rather than Flintronic. A bullet says medium strength comes off with standard tools and high strength after heating, and it both claims oil resistance and tells you to use clean, dry threads. UK reviews say both bottles leaked, caps were loose, and liquid was in the bag. One buyer says the red looked like cherry juice and did not work as a high-strength lock.
Pros
Cons
Best for: Only a spare you can afford to bin if the caps have already leaked in the bag.
Less suitable: Any fastener where you need a stated fill and a colour cell that matches the title.
Specifications
Common questions
How much liquid does the listing state?
There is no millilitre cell. The weight is 10 g and the package is 7.9 x 7.6 x 1.9 cm. Reviews describe two small bottles.
Do the title and the colour cell agree?
The title says blue and red, medium and high strength. The colour cell says Blue (MID-Strength) only.
What arrived damaged in UK reviews?
Reviewers say both bottles leaked, caps were loose, and liquid was in the bag. One buyer says the red looked like cherry juice and did not work as a high-strength lock.
The title says Bäder B270Eco high-strength green, 50 ml, at £10.95, with 4.6 from 156 ratings. The first bullet on the same page says medium strength, so the grade is not settled. A bullet gives −55 °C to +180 °C, and the water-resistance cell says waterproof. UK reviews say the concertina dispenser takes practice, the green shows where you have coated the thread, and a 50 ml fill may outlast the use-by date. Reviewers also call the liquid runny. The material cell says plastic, and the rank cell is Sewing Thread. The cells do not say how to remove it.
Pros
Cons
Best for: Only if you have checked the live title and the first bullet still describe the same strength.
Less suitable: A first bottle, because this listing does not settle medium versus high.
Specifications
Common questions
Is this medium or high strength?
The title says B270Eco high strength green. The first bullet says medium strength. Both lines are on the same listing. Treat that as a clash, not as a settled grade.
What temperature does the bullet state?
A bullet says -55 °C to +180 °C and uses the words 100% waterproof. The water-resistance cell also says waterproof.
What do reviews say about the bottle?
UK reviews say the concertina dispenser takes practice, the green shows coverage, and a 50 ml fill may outlast the use-by date.
The title says low-strength purple, 50 ml, at £10.95, with 4.6 from 109 ratings. The first bullet says low strength and then medium strength in the same sentence, so you cannot treat the grade as settled. The viscosity cell says low, and a bullet states −55 °C to +180 °C. A UK review says a screwdriver still undoes it with extra force, and another says it is useless on plastic fittings. The compatible-material cell says metal. The material cell says epoxy resin and the rank cell is Super Glue, which are catalogue labels rather than a use. Weight is 80 g.
Pros
Cons
Best for: A small metal screw only after you have read the live bullet and accepted that low and medium are both printed.
Less suitable: Plastic fittings, and anyone who needs one strength word before they buy.
Specifications
Common questions
Does the listing settle low versus medium strength?
The title says low strength purple. The first bullet says low strength and then medium strength in the same sentence. The listing does not resolve that.
Will it work on plastic?
The compatible-material cell says metal. A UK review says it reacts with metal and is useless on plastic fittings. The listing does not claim plastic.
What is the viscosity cell?
The viscosity cell says low. The volume is 50 millilitres and the weight is 80 g.
The title says 50 ml blue plus 50 ml red at £8.99, with 4.6 from 59 ratings. The item-volume cell says 100 millilitres and the unit count says 200.0 millilitres, so the fill is not one figure. A bullet gives −54 °C to 150 °C, which is a service band rather than a removal temperature, and it says medium strength needs a wrench while high strength needs heat and a wrench. Cure is stated as 15–20 minutes, then 24 hours. The model cell prints 242/262, the brand is sitarcmin, and the manufacturer is WEIKESITA, so that number is not a Loctite certificate. Country of origin is China, and compatible material says metal.
Pros
Cons
Best for: A pair of grades only after you treat 50 ml + 50 ml as the claim to check on the bottle, not the 200 ml unit count.
Less suitable: Anyone buying it as Loctite 242 or 262, or anyone who needs one fill figure.
Specifications
Common questions
How much liquid is stated?
The title says 50 ml + 50 ml. The item-volume cell says 100 millilitres. The unit count says 200.0 millilitres. Those three figures are all on the listing.
How does the listing say you remove it?
Medium strength with a wrench and more force. High strength with high-temperature heating and a wrench. The service bullet says -54 °C to 150 °C, which is not a removal temperature.
Is model 242/262 a Loctite grade?
The model cell prints 242/262. The brand cell is sitarcmin and the manufacturer cell is WEIKESITA. The listing does not say the bottles are Loctite.
This 50 ml kintsukuroi bottle is medium blue at £8.88, with 4.5 from 130 ratings. The bullet says you can undo it with common hand tools, with about 10 minutes to an initial set and about 24 hours to full strength. It also says the bottle is half full on purpose, because the stated 50 ml still needs air left in the bottle. UK reviews praise the lock and name screwdrivers and spanners. They also criticise the cap: the nozzle stays on the cap, one lid needed a vice, and fluid sprayed when the lid was closed. The surface cell lists worktops, baths, and sinks, while the use bullet says threaded metal. Country of origin is China.
Pros
Cons
Best for: You will use more than a 10 ml bottle of medium blue on metal threads, and you can live with an awkward cap.
Less suitable: A one-off bolt where a fiddly cap matters more than the extra liquid, and any surface that is not a metal thread.
Specifications
Common questions
Can it be undone?
The bullet says medium strength blue allows removal with common hand tools. A UK review names screwdrivers and spanners.
Why might the bottle look half empty?
The bullet says the bottle is half full on purpose and that the capacity is still 50 ml, because the liquid needs air to stay liquid.
What do reviews say about the cap?
UK reviews say the nozzle stays on the cap, a vice was needed to open one lid, and the lid sprayed fluid when closed.
The 50 ml Bäder medium blue is £10.95, at 4.3 from 140 ratings, which is the weaker star line among the Bäder bottles in this set. The title says high temperature resistant, but the cells on this listing do not give a degree figure, unlike the 10 ml sister listing. UK reviews compare the value with 242 and 243 grades and say the expiry month was rubbed off, describing the bottle as old stock. A review says larger threads needed heat or extra leverage to undo. The material cell says plastic while you are buying a threadlocker liquid. The fill is 50 millilitres and the weight is 82 g.
Pros
Cons
Best for: You already want this medium blue and you can read the date on the bottle in your hand before you rely on it.
Less suitable: A first buy if you need a printed temperature and a listing without an old-stock complaint.
Specifications
Common questions
What do UK reviews say about the date on the bottle?
Reviewers say the expiry month was rubbed off and describe the bottle as old stock. The listing itself does not print an expiry date.
How much is in the bottle?
The unit count is 50.0 millilitres. Weight is 82 g. Dimensions are 11.5 x 4.5 x 4.5 cm.
Does this listing state a temperature number?
The title says high temperature resistant. The cells on this listing do not give a degree figure. Water resistance in the cell is water resistant, not the sister listing's waterproof bullet.
The title says 2 × 5 ml, medium and high, at £3.99, with 4.3 from 24 ratings. The colour cell says Red (HI-Strength) only, and the package-quantity cell says 1. Weight is 10 g, the package is 5.7 × 4.8 × 1.5 cm, and the manufacturer cell is XJYEU. One of the two UK reviews says the red is a permanent lock and that two small bottles will not go far. The other says the lids leaked into the bag and counts four bottles. The shared bullet describes both a tool removal and a heat removal, which does not match a single high-strength colour cell. There is no volume cell and no cure time.
Pros
Cons
Best for: Nowhere in this set until the live page shows one strength, one fill, and caps that arrive closed.
Less suitable: A bolt you cannot afford to leave locked, and any order where a leaked bag is a problem.
Specifications
Common questions
Is this medium strength, high strength, or both?
The title says medium and high strength and 2 x 5 ml. The colour cell says Red (HI-Strength). The shared bullet describes both removal methods.
What did the two UK reviews say?
One says the red is a permanent lock and that two small bottles will not go far. The other says the lids leaked into the bag and counts four bottles.
Who is the manufacturer cell?
The manufacturer cell says XJYEU. The title brand is Flintronic. Weight is 10 g.
Scores use the twelve amazon.co.uk listings kept in this comparison. They are not a laboratory test and they do not rank every threadlocker sold in the UK. Other Loctite 243 packs exist outside this set and are not scored here. Each score is out of 100, from the four blocks below.
Review evidence
30%Up to 30 points from the amazon.co.uk star line and how much separate review evidence sits behind it. A 4.8 from 22 ratings scores far below a 4.6 from 5,126. Counts in the low hundreds sit in the middle.
Listing clarity
25%Up to 25 points when you can buy from the listing as it stands: one strength word, a colour cell that matches it, a millilitre figure, and no model name presented as a Loctite certificate.
Price against fill
25%Up to 25 points for price against a fill you can read. Shelf prices are the amazon.co.uk figures in this comparison. Pounds per millilitre are label arithmetic. A £3.99 title with no millilitre cell cannot win this block.
Review comments
20%Up to 20 points for review sentiment, with deductions for leaks, a rubbed-off expiry, a cap you cannot open, and a grade you undo only with heat when the job is a fastener you will service.
Buy the strength you can undo, then the fill you can read. A dye, a 4.8 from a thin review count, and a B243 name on another brand do not settle the grade.
A threadlocker is an anaerobic liquid. It cures to a hard plastic when air is shut out between close-fitting metal threads, so a fastener is less likely to walk loose under vibration. UK buyers on amazon.co.uk are choosing strength and fill size. Medium, often blue, is the grade if you will undo the joint with hand tools. High strength is the grade if you accept heat to remove it: green on Henkel's UK scale, red on many own-brand sets.
Henkel UK uses blue, green and purple, and treats red as a trademark. Own-brand pairs often use red for high. The purple Bäder bullet prints low and medium together, and the green 50 ml title says high while the first bullet says medium. Read the strength word on that listing.
A fixture of 10 to 20 minutes is not full strength. Where a time is printed, full cure is about 24 hours. Do not pour leftovers back into the bottle. Loctite 243's datasheet and the Vigorder bullet both say to keep unused liquid out of the bottle.
A 4.8 from 22 ratings is a thinner sample than 4.6 from 5,126. UK reviews also describe leaked caps, a red liquid that did not lock, a rubbed-off expiry month, and a cap that needed a vice. Those comments sit in the judgement beside the stars.
Strength decides whether you can service the fastener later. Medium is the grade when you will undo the joint with hand tools. High is the grade when the joint should stay, and you can heat it later. Low is for adjustment screws and for aluminium or brass at modest loads. Henkel UK prints blue, green and purple, and treats red as a trademark of that brand. Own-brand pairs in this set often print blue for medium and red for high. The Bäder 10 ml medium bottle is blue and says medium.
Price only means something against a fill you can read. The 5 ml Loctite tube is £6.60, about £1.32 per millilitre if the volume cell is what you receive, and the title also says 5 g. The kintsukuroi 50 ml is £8.88, about £0.18 per stated millilitre, which is why it is the best value among single-grade medium bottles. The Bäder 10 ml medium is £5.39, about £0.54 per millilitre, a small-bottle price with a readable fill.
Three typical situations, each with a recommendation from this comparison.
You lock car or bike bolts and you will undo them with hand tools. The Bäder medium blue 10 ml is about £5.39, with 4.7 from 229 ratings. UK reviews say the lock holds and that the screws can still be undone. B243Eco is the seller's name on that bottle.
You want the Loctite name on a small metal bolt and you accept the price per millilitre. The Normal 5 ml tube is £6.60, with 4.6 from 5,126 ratings, the largest review count here. The colour cell is transparent, and the title says 5 g while the volume cell says 5 ml.
You will use more than a 10 ml bottle of medium blue on metal threads, and you can live with an awkward cap. The kintsukuroi 50 ml is about £8.88, with 4.5 from 130 ratings, about £0.18 per stated millilitre. UK reviews praise the lock and criticise the cap.
The top pick is the Bäder B243Eco medium blue 10 ml at about £5.39. Medium, blue and 10 ml agree, it has 4.7 from 229 ratings, and UK reviews say it holds and can still be undone. B243Eco is the seller's name on that bottle. The best value is the kintsukuroi medium blue 50 ml at about £8.88, about £0.18 per stated millilitre, with the cap complaints left in the judgement. The £3.99 packs are cheaper on the shelf and do not state a fill you can divide. The other ten bottles have no award.
kintsukuroi medium blue, 50 ml
About £8.88 for a stated 50 ml of medium blue, about £0.18 per millilitre, with the cap complaints kept in the judgement.
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 on colour codes, cure, removal temperatures, COSHH and GB CLP. Listing prices, stars and review themes are from the amazon.co.uk extracts dated 15 October 2026. Prices move.
This page contains affiliate links to amazon.co.uk. A qualifying purchase can earn us a commission at no extra cost to you. Scores follow the method above and the listings named here. They are not a laboratory torque test.
