The best medium strength threadlockers, compared.
Top pick: Vigorder blue 50 ml Best value: Bäder B243Eco blue 10 ml – About £5.39 for a bottle that prints medium-strength blue, with 4.7 from 229 reviews and UK texts that say the fastener could still be undone. No cure time is printed. Updated October 2026.
A medium-strength threadlocker is an anaerobic liquid that cures in a close metal thread, so vibration is less able to unwind a bolt you still expect to undo with hand tools. On amazon.co.uk the usual job is a bike, a motorbike, a car or a household fastener. Buy the bottle whose title, colour and removal line agree. A cell that says transparent, aerosol, plastic or high-strength red is a conflict, not a second feature. High-strength red, or a 270-class lock, may need heat. Loctite 243 is UK reference for the medium job, and that data sheet is not every blue bottle in the aisle. The [medium-strength threadlocker buying guide](/hub/diy-supplies/threadlocker-medium-strength/sub/threadlocker-medium-strength-buying-guide) covers strength, pack size and listing conflicts without this ranking. Low strength, often purple and the 222 class, is for screws you adjust often.
A medium-strength threadlocker is an anaerobic liquid that cures in a close metal thread, so vibration is less able to unwind a bolt you still expect to undo with hand tools.
42 products checked · 64 hrs invested · +22,100 readers
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Personal buying guide
Question 1 of 2
What must the bottle do?
The Vigorder LSJS-001 is a medium-strength blue 50 ml bottle at £7.99, and the bullets limit it to metal threads. They give a 20-minute first cure and full strength at 24 hours, and they describe the half-full bottle as intentional. amazon.co.uk shows 4.8 from 22 reviews, the highest star line in this set, and five UK reviews on the listing show no repeated fault. The bullets do not say whether you undo the bolt with hand tools or treat the lock as permanent. A question about plastic threads is unanswered, and a question about food containers has no food-safe cell on the listing. The page says to keep the liquid off skin and eyes. It is the top pick on the score in this comparison, and the thin review sample plus the missing removal line are the limits.
Pros
Cons
Best for: A metal thread when you want one blue 50 ml bottle and you will read the label for removal
Less suitable: Plastic threads, a food-contact job, or a buyer who wants hundreds of UK reviews before paying
Specifications
Common questions
Can you use it on plastic threads?
The precaution bullet says only metal threads. A question asks about plastic. There is no answer on the listing.
Does the listing say the bolt can be removed?
A question asks. The bullets do not say hand tools or permanent. They do say 20 minutes to first cure and 24 hours to full strength.
Is it described as food safe?
No. A question asks about food containers. There is no food-safe cell and no answer on the listing.
This Loctite 243 listing prints medium strength, blue, and 5 ml in the title, at £12.59, with 4.7 stars from 2,990 reviews. The bullets say it works on all metals and tolerates minor contamination, and the full-cure cell says 24 hours. Ten UK reviews say a few drops are enough, and two say the bottle is expensive or smaller than expected. The catalogue then fights the title: the container cell says aerosol can, water resistance says not water resistant, and compatible materials include glass, plastic and rubber while the material cell says Plastic. Part number 1370535 is on the page. It is the row in this set that actually prints 243, and you are paying £12.59 for 5 ml beside cells that do not match the bullets.
Pros
Cons
Best for: A buyer who wants the grade number 243 printed on a 5 ml blue bottle and will ignore conflicting cells
Less suitable: A large job, or anyone who needs the catalogue cells to agree with the title
Specifications
Common questions
Does the title say Loctite 243?
Yes. The title and item type say Loctite 243, medium strength, blue, 5 ml. Part number 1370535.
What contradicts the title?
The container cell says aerosol can. Water resistance says not water resistant. Compatible materials include glass, plastic and rubber. The material cell says plastic. The bullets say all metals.
What do the UK reviews say about the size?
Ten UK reviews are on the listing. Buyers say a few drops work. Two say it is expensive or smaller than expected for the money.
The Nanoxa pack is two bottles, blue and red, titled 50 ml each, at £12.99, with 4.7 stars from 528 reviews. The bullet calls the blue medium-strength locker removable and the red high-strength locker permanent, and the removable sentence is cut off on the listing. It states 20 minutes to first cure and 24 hours to full strength, and it says each bottle holds 50 ml in a 100 ml container so that air remains. One UK review calls the half bottle a con, and another says the blue cap opens and pours. The material cell says Plastic while the title says the liquid is for nuts, bolts and metals. You are buying a serviceable locker and a permanent one in the same order, so the red bottle is the wrong choice if that bolt must come apart.
Pros
Cons
Best for: A workshop drawer that genuinely needs both a removable blue locker and a permanent red one
Less suitable: A single serviceable bolt, or anyone who might grab the red bottle by mistake
Specifications
Common questions
Which bottle is the one you can undo?
The bullet calls the blue medium-strength locker removable and the red high-strength locker permanent. The removable sentence is cut off on the listing.
Why is the bottle half full?
The bullet says each bottle has 100 ml capacity and 50 ml of product so air remains. One UK review calls the half bottle a con. Another says the blue cap opens and pours.
What is the material cell?
Plastic. The title says the liquid is for nuts, bolts and metals.
The Bäder B243Eco is a medium-strength blue liquid in a 10 ml bottle, priced at £5.39 on amazon.co.uk. Across 229 reviews the listing sits at 4.7 stars, and the UK reviews say screws stayed tight and could still be undone for cleaning, including nuts that were not too hard to shift. The bullets state −55°C to +180°C, oily screws, and a waterproof claim, with metal as the surface. There is no cure-time cell, so this page does not tell you a fixture time or a 24-hour full cure. A Green Line bullet calls the liquid non-hazardous, and the listing has no safety data sheet behind that line. At this price and review count it is the best value here for a bottle that actually prints medium strength, with the missing cure clock as the limit.
Pros
Cons
Best for: A metal fastener you still expect to undo, when you want a small medium-strength blue bottle at £5.39
Less suitable: Plastic threads, a joint that must never come apart, or a buyer who needs a printed fixture time
Specifications
Common questions
Does the listing say you can undo the bolt?
The bullets do not say hand tools or permanent. UK reviews say screws stayed tight and could still be undone for cleaning, and that nuts were not too hard to undo.
What temperature does the listing print?
The bullet states −55°C to +180°C and calls the liquid waterproof. There is no cure-time cell.
Is non-hazardous a classification on this listing?
No. It is a Green Line bullet. The listing has no safety data sheet and no hazard codes.
Loctite Normal is a small tube at £6.60, and amazon.co.uk shows 4.6 from 5,126 reviews, the largest count in this set. The title says 1 × 5 g and does not print medium strength or 243. The colour cell says Transparent, the volume cell says 5 millilitres, and the weight cell says 7 g, so the fill is not one figure. All 50 stored texts are from the United Kingdom, and buyers say it holds car and bike bolts. Several say there is very little in the bottle for the price, and one wanted a pointed applicator. The rank line places it first in Car Exhaust Seals, which is a catalogue slot rather than a threadlocker test. It is a widely reviewed Loctite tube, and it is not a labelled medium-strength 243 bottle.
Pros
Cons
Best for: A small Loctite tube for ordinary metal nuts when you accept a grade that only says Normal
Less suitable: A buyer who needs the words medium strength or 243 on the title
Specifications
Common questions
Does this listing say medium strength or 243?
No. The title does not. The item type is Loctite Threadlocker Normal 5ml. The colour cell is Transparent.
Is the fill 5 g or 5 ml?
The title says 1 x 5 g. The volume cell says 5 millilitres. The weight cell says 7 g.
What do the UK reviews say about the amount?
All 50 texts are from the UK. Buyers say it holds car and bike bolts. Several say there is very little in the bottle for the price, and one wanted a pointed applicator.
The Flintronic title says blue and red, medium and high strength, at £3.99, while the colour cell says Blue (MID-Strength) only. There is no millilitre cell, and the weight is 10 g. The bullet says medium strength comes off with standard tools and high strength needs heat, then standard tools, and no minute or hour cure time is printed. The star line is 4.6 from 381 reviews, and the opening UK texts match the 4 × 5 ml listing, including a Segway job and leaked bottles, so they are one shared set of reviews rather than two samples. The manufacturer cell says XJYEU. It is the lowest shelf price in the set, and you cannot tell from the cells whether a red bottle is in the parcel.
Pros
Cons
Best for: A very cheap trial only if you open the parcel and check which colour actually arrived
Less suitable: Anyone who needs a stated millilitre volume or a review sample that belongs to this ASIN alone
Specifications
Common questions
Is this one bottle or two colours?
The title says blue and red, medium and high strength. The colour cell says Blue (MID-Strength) only. There is no millilitre cell. Weight is 10 g.
How does the bullet say you remove it?
Medium strength with standard tools. High strength needs heat, then standard tools. No minute or hour cure time is printed.
Are the 381 reviews only for this ASIN?
The star line and the opening UK texts match B0FH53QR2W, including a Segway job and leaked bottles. Treat them as one shared set of reviews.
The title says four 5 ml blue medium-strength bottles at £4.99, and the size cell says 20ML, with a weight of 20 g. The colour cell is Blue (MID-Strength). The 4.6 from 381 reviews, the image line, and the opening UK texts match the blue-and-red listing, and those texts mention a red bottle, so they are not a separate sample for this blue-only title. The shared bullet still describes high strength that needs heat, which this colour cell does not. Package quantity is 1. You might be buying four small blue bottles, or you might be looking at catalogue fields copied across two ASINs. Treat the review count as shared evidence, not as 381 fresh opinions of this pack.
Pros
Cons
Best for: A small blue-only multipack if the bottles in the parcel match the four-piece title
Less suitable: A buyer using the 381-review line as proof of this ASIN on its own
Specifications
Common questions
How much is in the pack?
The title says 4 pieces of 5 ml. The size cell says 20ML. Weight is 20 g. Package quantity is 1.
Why do the reviews mention a red bottle?
The opening UK texts are the same as on B0FH52BTTS, whose title is blue and red. They are not a separate 381-review sample for this blue-only title.
Does the bullet mention heat?
Yes. The shared bullet says medium strength comes off with standard tools and high strength needs heat first. This colour cell is mid-strength blue.
The Realth pack is three 10 ml bottles, blue, red and purple, at £8.99, with 4.6 stars from 222 reviews. The bullet assigns low strength to temporary fixes, medium to everyday tasks, and high to permanent or heavy-duty projects, and the full-cure cell says 24 hours. It does not say hand tools or heat. The title describes three bottles, the item-volume cell says 10 millilitres, and the unit count says 30.0 millilitres, against a listed weight of 20 g. The compatible-material cell says Plastic and the material cell says acrylates, while a bullet also calls the set a leak-proof water bottle. Country of origin is listed as Chile. The medium bottle is only one of three grades, and the plastic cell means this is not a clean metal-only locker.
Pros
Cons
Best for: Someone who wants a low, a medium and a high bottle and will check the label against the plastic cell
Less suitable: A metal-only job, or a buyer who needs one volume figure they can trust
Specifications
Common questions
How many bottles are in the pack?
The title and the included-components cell say three 10 ml bottles, blue, red and purple. The item-volume cell says 10 millilitres. The unit count says 30.0 millilitre. Weight is 20 g.
What does the listing say each strength is for?
The bullet says low for temporary fixes, medium for everyday tasks, and high for permanent or heavy-duty projects. It does not say hand tools or heat.
Does the catalogue say metal?
The compatible-material cell says plastic. The material cell says acrylates. A bullet also calls the set a leak-proof water bottle.
The sitarcmin set is blue medium and red high, titled 50 ml plus 50 ml, at £8.99, with 4.6 stars from 59 reviews. The bullet says the blue liquid can be taken apart with tools and the red is for a permanent fixing, with fixture in 15–20 minutes, full cure at 24 hours, and a temperature line of −54°C to 150°C. The item-volume cell says 100 ml and the unit count says 200.0 millilitres, so the pack size is not one number. The manufacturer cell says WEIKESITA and the model number is 242/262. Seven of 21 stored texts are headed United Kingdom; they call it good value, and one notes that the bottles look large because they are half full, which the bullet says is intentional. The blue side matches a tool-removable job, and the 200 ml unit count plus the permanent red bottle are what you check before you pay.
Pros
Cons
Best for: A two-colour pack when you will use the blue bottle on metal and leave the red bottle sealed
Less suitable: A buyer who needs one agreed volume, or a job that must stay serviceable
Specifications
Common questions
How much liquid does the listing claim?
The title says 50 ml + 50 ml. The item-volume cell says 100 ml. The unit count says 200.0 millilitre.
Which colour comes apart later?
The bullet says the blue medium-strength liquid can be disassembled with tools. It says the red high-strength liquid is for permanent fixing.
Are the UK reviews a large sample?
Seven of 21 texts are headed United Kingdom. They call it good value. One notes the bottles look large because they are half full, which the bullet says is intentional.
The kintsukuroi bottle is medium-strength blue, 50 ml, at £8.88, and the bullets say you remove it with ordinary hand tools. They also print a 10-minute fixture and a 24-hour full cure, which is a clearer clock than several rows in this set. amazon.co.uk shows 4.5 from 130 reviews. A bullet says the half-full bottle is the intended fill because the liquid is anaerobic, and that is a listing claim rather than a measured volume. UK reviews name screwdrivers and spanners, and one reviewer used it on caliper bolts. Two UK reviews say the nozzle stays on the cap, or that the lid needed a vice and sprayed fluid when it was closed. You get a printed removal method, and the cap is the complaint that comes up more than once.
Pros
Cons
Best for: A larger medium-strength blue bottle when you want hand-tool removal and a 24-hour cure printed on the page
Less suitable: Anyone who has already fought a stuck nozzle, or a job that needs a stated temperature range
Specifications
Common questions
Can this listing be undone with hand tools?
The bullet says removal with common hand tools. UK reviews name screwdrivers and spanners, and one review used it on caliper bolts.
Why does the bottle look half empty?
The bullet says the half bottle is the correct capacity because the liquid is anaerobic. That is a listing claim, not a measured fill.
What do UK reviews say about the cap?
Two UK reviews say the nozzle stays on the cap or that the lid needed a vice and sprayed fluid when closed.
The title says Loctite 243, 50 ml, blue, at £12.00, and the special-features cell says oil tolerant and removable. The manufacturer cell says DGI, not Henkel, while the brand cell still says Loctite. amazon.co.uk shows 4.4 from 36 reviews, and nine UK texts say it locks and can still be undone. One review calls it an unlawful UK product and another says the stock is from India and takes over a week; those lines are reviews, not an enforcement notice. Package quantity says 10 while the number of pieces says 1, and the material cell says synthetic rubber against a compatible-material line of stainless steel. There is no cure-time cell and no temperature cell. The larger fill looks cheaper per millilitre than the 5 ml 243 row only as shelf arithmetic, and the manufacturer mismatch is the reason to pause.
Pros
Cons
Best for: A 50 ml bottle labelled 243 only if you have checked that DGI is the seller you meant to buy
Less suitable: A buyer who wants a Henkel manufacturer cell, a cure time, or a clean supply story
Specifications
Common questions
Who is the manufacturer on this listing?
The manufacturer cell says DGI. The brand cell says Loctite. The title prints Loctite 243, 50 ml.
Does the listing say it is removable?
The special-features cell says oil tolerant and removable. There is no cure-time cell and no temperature cell.
What do the UK reviews say about the supply?
Nine UK texts. Several say it locks and can still be undone. One calls it an unlawful UK product. One says the stock is from India and takes over a week. Those are reviews, not an enforcement notice.
The title says medium and high strength, red, 2 × 5 ml, at £3.99, and the colour cell says Red (HI-Strength). amazon.co.uk shows 4.3 from 24 reviews, a separate star line from the 381 shared by the other two Flintronic rows. One of the two UK reviews calls the red a permanent lock that should not come undone, and says the bottles are small. The other says all four lids leaked into the bag, while the title says two pieces. The bullet still says medium strength comes off with tools and high strength needs heat. There is no cure-time cell. Leave this row if the bolt has to be serviced, because the colour cell is high strength and the UK texts describe a permanent lock.
Pros
Cons
Best for: A permanent metal fixing only if you meant to buy high-strength red and you accept a thin review sample
Less suitable: Any bolt you expect to undo with a spanner, or a buyer who wanted medium strength
Specifications
Common questions
Is this medium strength or high strength?
The title says both. The colour cell says Red (HI-Strength). One of the two UK reviews calls the red a permanent lock.
What did the UK reviews report?
Two UK texts. One says the bottles are small and the lock should not come undone. One says all four lids leaked into the bag. The title says two pieces.
Is the 4.3 from 24 the same reviews as the 381?
No. This star line is 4.3 from 24. The 4.6 from 381 belongs to the other two Flintronic ASINs.
Scores use the twelve amazon.co.uk listings read on 15 October 2026. Points follow the star line and review count, whether the title prints medium strength and a removal line, and whether pack, colour, container and manufacturer agree. Catalogue conflicts, a non-Henkel manufacturer on a 243 title, reviews shared by two ASINs, and a very thin UK text sample reduce the score. Nothing was torque-tested in a lab.
Star line and review count
25%The amazon.co.uk star rating and how many reviews sit behind it. A thin UK text sample, or a 4.6-from-381 line shared by two ASINs, scores once, not twice.
Medium strength and removal
25%Whether the title prints medium strength, and whether removal with hand tools is stated. A high-strength colour cell beside a medium title loses points.
Pack, colour and maker
20%Whether pack size, colour, container and manufacturer agree with the title. A 5 g title against a 5 ml cell, or an aerosol cell on a bottle, is a conflict.
Catalogue conflicts
20%Deductions for a cell that fights the title, a non-Henkel manufacturer on a Loctite 243 title, and reviews shared across two listings.
Shelf price for a clear bottle
10%The amazon.co.uk price against a bottle that prints medium strength and has a UK removal story. A cheaper row with a conflicting colour cell does not take the value place.
Start with the job, not the colour on the cap. Medium strength means you still expect to undo the bolt with hand tools. High-strength red may need heat, and a purple low-strength liquid is for screws you adjust often. Then check that the bottle is for metal, that the pack size is one figure, and that fixture is not treated as full cure. A cell that fights the title stays a problem on that row. Twelve amazon.co.uk listings were read on 15 October 2026, from £3.99 to £12.99.
A medium-strength threadlocker is an anaerobic liquid that cures in a close metal thread. Vibration is then less able to unwind a bolt you still expect to undo with hand tools. High-strength red, or a 270-class lock, may need heat. Low strength, often purple and the Loctite 222 class, is for screws you adjust often. UK shoppers on amazon.co.uk are usually locking a bike, a motorbike, a car or a household fastener. The useful buy is the bottle whose title, colour and removal line agree.
High-strength red, or a 270-class lock, may need heat. Amazon red is not Loctite 270. If you still expect a spanner to undo the bolt, the medium blue side is the one these listings describe as removable.
Fixture on these bullets is 10, 15–20 or 20 minutes. Full cure, where it is printed, is 24 hours. Do not load the joint at the first number, and do not turn the fastener after cure has started.
Transparent, aerosol, plastic, or a red high-strength cell beside a medium title stays on that row. A deliberate air gap on Nanoxa, sitarcmin, Vigorder and kintsukuroi is a listing claim, not a measured short fill. A leaked cap is a different fault.
Medium strength means you still expect to undo the fastener with hand tools. High-strength red, or a 270-class lock, may need heat. Low strength, often purple and the Loctite 222 class, is for screws you adjust often. In the sets on this page the blue side is the removable or everyday bottle, and the red side is described as permanent or high strength. Amazon red is not Loctite 270, and not every blue bottle is Loctite 243. The liquid is for metal unless that bottle states a plastic grade.
The pack has to be one figure. Titles, volume cells, unit counts and half-full bullets disagree. A 5 ml named bottle and a 50 ml no-name bottle are different buys. The sitarcmin title says 50 ml plus 50 ml, the item volume says 100 ml, and the unit count says 200 ml. The Realth title is three 10 ml bottles while the volume cell says 10 ml. Bullets on Nanoxa, sitarcmin, Vigorder and kintsukuroi say the air gap is intentional. That is a listing claim, not a measured fill.
Three typical situations, each with a recommendation from this comparison.
You are locking a lamp, a handle or a vibrating screw, and you still expect to undo it. The Bäder B243Eco is medium-strength blue, 10 ml, at about £5.39, with 4.7 from 229 reviews. UK texts say fasteners could still be undone. The listing prints no cure time, so you do not get a fixture clock from the page.
You are locking a crank, a fairing or a cover, and you will undo it later. Stop if the manual names another grade. The kintsukuroi 50 ml bottle prints removal with hand tools, a 10-minute fixture and a 24-hour full cure, at about £8.88. UK reviews also mention a stuck nozzle.
You are issuing a bottle to staff, so the safety data sheet and COSHH sit with the employer. The Loctite 243 5 ml title prints the grade Henkel’s GB sheet names, at about £12.59. The container cell says aerosol can, and the material cell says plastic. Do not copy H317 and H412 onto a no-name bottle.
The top pick is Loctite 243 blue 5 ml, with the highest score in this comparison (9.4 out of 10, from 2,990 amazon.co.uk reviews). The best value among bottles that print medium strength and have a UK removal story is the Bäder B243Eco 10 ml at about £5.39, with 4.7 from 229 reviews. The limit is a missing cure-time cell. The cheaper Flintronic rows do not take that place: one colour cell fights the title, two ASINs share one 4.6-from-381 review line, and the red row’s colour cell is high strength.
Bäder B243Eco blue 10 ml
About £5.39 for a bottle that prints medium-strength blue, with 4.7 from 229 reviews and UK texts that say the fastener could still be undone. No cure time is printed.
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.
Henkel, the Health and Safety Executive, ISO 10964 and the Consumer Rights Act 2015, plus the amazon.co.uk listings read on 15 October 2026. Prices move. Nothing was torque-tested in a lab.
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. Scores compare published listings and review texts. They are not a laboratory test.
