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Loctite Threadlocker Blue 242 - Deal
Price as of June 16, 2026 — check Amazon for the current price.
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By Patrick Smith · Updated July 10, 2026 · How we review
Loctite Blue 242 solves a specific problem: bolts and screws that vibration slowly backs out. A single drop on the threads cures into a plastic-like lock once the fastener is tightened — strong enough to hold through engine and equipment vibration, yet still removable with ordinary hand tools, which is the whole difference between blue and the permanent red grades. Two things trip up first-time users. The threads must be clean and oil-free for 242 to cure properly; the newer 243 formula tolerates light oil contamination, which is why some mechanics have switched to it. And less is more — flooding a fastener just leaves hardened residue to scrape off. The tiny tube looks expensive per ounce until you realize each job uses a drop and it lives in a toolbox for years.
Our verdict
The default choice for any metal fastener you want to stay put but might remove later. If you can't fully degrease the threads, buy 243 instead.
What buyers say
Our summary of recurring themes in customer reviews on the Loctite Threadlocker Blue 242 Amazon listing (read July 2026) — not quotes or endorsements.
Most praised
Users treat blue Loctite as the standard fix for fasteners that back out, praising how reliably a single drop holds through vibration and how long one tube lasts.
Most common complaint
The recurring caveat is surface prep: 242 needs clean, oil-free threads to cure, and forum users note the 243 successor works on lightly oily hardware — several also warn against over-applying, which leaves messy hardened residue.
Worked best for
Best for automotive, mower, bike and household bolts subject to vibration; not the right pick for oily threads or plastic parts.
Why buy the Loctite Threadlocker?
- Medium-strength hold: resists vibration, removable with hand tools.
- Designed for metal fasteners roughly 1/4" to 3/4" in diameter.
- A drop per fastener — one small tube lasts years in a toolbox.
Hand-picked deal
One of our top trending picks in Auto & Tools.
Live best price
We link straight to Amazon so you always see today's real price.
Fast shipping
Fulfilled by Amazon — fast, often Prime, delivery.
Easy returns
Backed by Amazon's secure checkout and return policy.
Was $6.31 — prices change fast on Amazon
Price as of June 16, 2026. Tap to see the current price.
The Loctite Threadlocker Blue 242 is one of the Auto & Tools deals worth grabbing right now.
Loctite Threadlocker Blue 242 - Deal
Stop bolts backing out under vibration — without making them permanent.
Loctite Threadlocker Blue 242 at a glance
- Product
- Blue 242
- Brand
- Loctite Threadlocker
- Category
- Auto & Tools
- Price
- $6.31 (as of June 16, 2026)
- Availability
- In stock on Amazon
- Condition
- New
- Shipping
- Fast, often Prime
- Returns
- Amazon return policy
The Promolyze promise on every pick
Quality you can check
Why trust these picks
Secure and simple
Don't let the Loctite Threadlocker Blue 242 sell out.
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Frequently asked questions
Can I remove a bolt treated with Loctite 242?
Yes — that's the point of the blue grade. It is rated as medium strength, so fasteners break loose with ordinary hand tools. Red threadlocker is the permanent grade that typically needs heat to release.
What's the difference between Loctite 242 and 243?
Both are medium-strength blue threadlockers. 243 is the newer formulation with better tolerance of slightly oily threads and higher temperature resistance; 242 wants clean, degreased threads. Forum users report using them interchangeably on clean hardware.
How much should I apply?
One drop onto the engaged threads is enough for most fasteners. Applying more doesn't add holding power — it just squeezes out and hardens into residue around the joint.
Loctite Threadlocker
$6.31