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How to apply threadlocker

Updated: October 2026

You have a metal bolt that walks loose, a bottle in your hand, and a wish to put the liquid in the right place without treating a ten-minute set as a finished joint. This is how to apply threadlocker on a household or bicycle fastener: clean metal, a few drops, assemble, and wait about a day before you trust it. Peter F. used Loctite's UK consumer guide, Henkel's Loctite 243 application notes, and the cure bullets on the bottles in our [threadlocker comparison](/hub/diy-supplies/threadlocker). He did not run a lab test. A qualifying purchase can earn us a commission at no extra cost to you.

You have a metal bolt that walks loose, a bottle in your hand, and a wish to put the liquid in the right place without treating a ten-minute set as a finished joint.

Our top picks

Bäder Bäder B270Eco high green, 10 ml

Best overall

Bäder Bäder B270Eco high green, 10 ml
7.6/10about £5.45
View offer
Bäder Bäder B243Eco medium blue, 10 ml

Rank 2

Bäder Bäder B243Eco medium blue, 10 ml
8.4/10about £5.39
View offer
kintsukuroi kintsukuroi medium blue, 50 ml

Preis-Tipp

kintsukuroi kintsukuroi medium blue, 50 ml
6.9/10about £8.88
View offer
On this page
  1. 1.Before you open the bottle
  2. 2.Where the drops go
  3. 3.How long it takes
  4. 4.Oil, leftovers, and a half-full bottle
  5. 5.When you stop

Before you open the bottle

Use it on metal threads. Loctite's UK consumer guide and Henkel's colour article are written for metal, and the compatible-material cells in this set say metal. It will not cure the way you want on plastic. If the screw is in plastic, or the part is a watch bracelet, this liquid is the wrong product. Choose a strength you can undo if you will service the joint. Medium is the bottle for a fairing bolt or a rack bracket. High strength is for a fastener you intend to leave. Brakes, steering, suspension, and fuel fittings are a mechanic's job. Shake the bottle, and keep the liquid off your skin and eyes. Which strength to buy is on the threadlocker buying guide.

Where the drops go

The liquid cures without air, between the mating threads, once they are assembled. A puddle on the head of the bolt does nothing useful. Loctite's consumer guide puts drops on the engagement threads of the male fastener, leaving the first thread clear. Wipe the excess after you have tightened it. A blind hole is different. The consumer guide puts the liquid at the bottom. Henkel's Loctite 243 how-to puts it in the lower third. That detail is for 243, not a part number to copy onto Bäder or Flintronic. If you only wet the mouth of a blind hole, the bolt pushes the liquid out. Assemble straight away and tighten before the liquid fixtures.
Bäder Bäder B270Eco high green, 10 ml

Testsieger

Bäder Bäder B270Eco high green, 10 ml
7.6/10about £5.45
View offer

How long it takes

A joint that feels dry in a few minutes is not at full strength. Loctite's consumer guide says a set of about 10 minutes and a full cure of about 24 hours. Follow the bottle you opened. kintsukuroi says about 10 minutes and 24 hours. sitarcmin says 15 to 20 minutes and 24 hours. Nanoxa and Vigorder say 20 minutes and 24 hours. The Bäder 10 ml bottles do not print a cure time, so about 10 minutes and about 24 hours is a rule of thumb until the bottle in your hand says otherwise. Do not load the joint at the fixture time. Leave it about a day if you can. A cold garage is a reason to wait longer, not a reason to bake the part.

Oil, leftovers, and a half-full bottle

Degrease the threads unless the bottle you are holding says it tolerates oil. Vigorder says clean and dry metal only. Several Bäder bullets say the liquid secures slightly dirty and oily screws. That offer belongs to the Bäder bottles that print it. Wipe the obvious oil off. Flintronic claims oil resistance and also says clean and dry, so that page has not given you one instruction. Wipe unused drops off. Do not pour them back. Liquid that has touched a thread can start to cure and spoil the rest. A new bottle that looks half empty is often packed that way: kintsukuroi, Vigorder, and Nanoxa say the air gap is deliberate. A cap that leaked in the bag is a different fault.

When you stop

Stop before you heat a joint, and before you treat a safety-critical fastener as a practice piece. Brakes, steering, suspension, and fuel lines are for a mechanic. If you are still choosing a dye, use blue vs red threadlocker. If the title and the first bullet name two strengths, as the purple and green 50 ml Bäder pages do, do not guess. A cured medium joint comes apart with hand tools first. A cured high-strength joint is a heat job. If the bolt is already stuck, go to how to remove threadlocker instead of adding more.

Common questions

Do you put the liquid on the bolt or in the hole?
On a through-hole, put drops on the male threads that will engage, and leave the first thread clear, which is the Loctite consumer method. In a blind hole, put the liquid at the bottom, or in the lower third if you are following Henkel's Loctite 243 note. Then assemble and wipe the excess. Liquid only on the bolt head does not lock the threads.
How long until you can rely on it?
Allow about 24 hours for a full cure. Fixture claims in this set are about 10 minutes on kintsukuroi, 15 to 20 minutes on sitarcmin, and 20 minutes on Nanoxa and Vigorder. Loctite's consumer guide says about 10 minutes to set. Do not treat that first interval as full strength, and do not load a freshly assembled bracket as if the day had already passed.
Should you degrease first if the bottle says it tolerates oil?
Wipe visible oil off either way. Use a slightly oily thread only when that bottle says so. Bäder bullets on the bottles that print the line are the ones making the offer. Vigorder says clean and dry. One brand's oily-thread sentence is not a rule for the bottle next to it.
Will it work on plastic?
No. The guides and the material cells in this set are for metal. A review says the purple Bäder liquid does not lock plastic fittings, and watch-link reviews of the clear Loctite tube say it failed. Do not use it on plastic housings or as a general glue.
When should a mechanic take over?
Before you touch brakes, steering, suspension, or fuel fasteners, and before you heat a joint you do not understand. Also hand over a bolt that will not move in a tapped hole rather than forcing it. Applying threadlocker to a household or bicycle bracket is the job this page describes. Inventing a torch step on a vehicle is not.

Related pages

Threadlocker medium strength comparison

Threadlocker

Best threadlocker for bolts you will undo with tools

Blue vs red threadlocker: hand tools or later heat

Threadlocker buying guide: strength, colour and fill

How to remove threadlocker with tools or localised heat

Sources

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.

  1. Henkel UK, blue, green and purple threadlockers (retrieved 15 October 2026)
  2. Loctite consumer UK, how threadlocker works (retrieved 15 October 2026)
  3. Henkel, how to remove high-strength threadlocker (retrieved 15 October 2026)
  4. LOCTITE 243 technical data sheet (retrieved 15 October 2026)
  5. LOCTITE 270 technical data sheet (retrieved 15 October 2026)
  6. ISO 10964:1993, torque method (retrieved 15 October 2026)
  7. HSE, COSHH assessment (retrieved 15 October 2026)
  8. Control of Substances Hazardous to Health Regulations 2002 (retrieved 15 October 2026)
  9. HSE, GB CLP (retrieved 15 October 2026)