Thread Locking and Bearing Retention

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29 Jan 2013 07:09 - 29 Jan 2013 07:27 #1 by dandjcr
dandjcr created the topic: Thread Locking and Bearing Retention
The Dana 80 topic branched off into thread locking and and bearing retaining products so I've started a new topic.

Here's a useful Loctite selection chart for retaining rotating components.

There's lots more useful reading in the Loctite library here , and more useful info in our own Tech Docs library, (Workshop info, quick access here ).

David and Janet Ribbans - Oka 148
Oka148 profile here.
Visit our technical and travel blogs: here.
Last Edit: 29 Jan 2013 07:27 by dandjcr.

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29 Jan 2013 07:14 #2 by dandjcr
dandjcr replied the topic: Thread Locking and Bearing Retention
Here are a few Loctite FAQs that I didn't know.

The full list is here .

Q: How do you define anaerobic in relation to your products?

A: Anaerobics, that include many of our threadlockers, pipe sealants, retaining compounds and flange sealants, are products that cure in the absence of air. These are products that are designed for metal-to-metal assemblies although they are sometimes used for other materials as well. The presence of metal (ions) accelerates the cure of these products. When you assemble parts with an anaerobic and you have excess squeeze out, outside the joint, this will not harden due to the anaerobic nature of the product. Simply wipe the excess away with a common solvent like acetone or isopropyl alcohol. Typically anaerobics fully cure in 24 hours at room temperature under normal ambient conditions when properly used.

Q: If anaerobics cure in the absence of air, how come they don't cure in the sealed bottle?

A: The anaerobic bottles are specially formulated oxygen-permeable polyethylene bottles that allow air to pass through the wall of the bottle to maintain stability of the liquid product inside the container. The bottle is also not filled to the top for stability purposes. A 50 ml bottle does indeed contain 50 ml's of product in a larger bottle.

Q: I cannot get an assembly apart where a threadlocker was used. What solvent will break the threadlocker down?

A: No solvent will wick into the joint to break the threadlocker down. This is either hand tool removable at room temperature or if not, it requires high temperatures of 450-600°F to separate parts. The products are thermoset plastics in the cured state that soften at higher temperatures. Thus, you need to disassemble while at the higher softening point temperature. Do not let this cool down first. Otherwise, it will resoldify. Solvents like methyl ethyl keytone and methylene chloride can be used for clean up of residue only after disassembly.

Q: Can I use a threadlocker for non-threaded assemblies like locking bearings or bushings in housings or on shafts?

A: Yes, you can. Traditionally we recommend retaining compounds like 609 or 603 but threadlockers are the same base chemistry and could be substituted in many cases. In fact, years ago Threadlocker 271 was referenced as Stud & Bearing Mount. Inversely, you could use retaining compounds to lock threads as long as you're cognizant of the fact that most will permanently lock threads.

Q: Can the cure of anaerobics be accelerated via heat?

A: Yes, you can heat cure anaerobics to achieve faster full cure. Typically you can heat cure these products at 250°F (125°C) for about one (1) hour or go as low as 150°F (66°C) for about three (3) hours. The one trade off is the fact that you will probably reduce your ultimate strength some. Whenever you accelerate the cross-linking of the polymer, you can reduce your ultimate strength. Carefully test for suitability.

Q: Do I need to use a primer with anaerobics?

A: We recommend the use of primers such as 7649 & 7471 with most anaerobics where both parts are classified as "inactive" metals. These metals lack the presence of iron or copper content and thus, lack the "active" metal ions required to fully cure the product in 24 hours. These metals include plated parts, stainless steel, galvanized steel and anodized aluminum, to name a few. If, on the other hand, both or at least one part is an "active" metal, such as plain steel, brass, bronze, copper or iron, there is no need to use a primer to ensure full cure in what is typically 24 hours at room temperature.

Slightly biased (?) chart from Loctite:


David and Janet Ribbans - Oka 148
Oka148 profile here.
Visit our technical and travel blogs: here.
The following user(s) said Thank You: Joseph Baz, Paul Scherek

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