Threadlocker Selection Chart

What it is

A threadlocker is an anaerobic adhesive. It stays liquid in air and cures into a solid plastic when it is confined between metal threads with no air. The cured film fills the gap between threads, which stops loosening from vibration and seals against leaks and corrosion. ASTM D5363 is the specification for anaerobic single-component adhesives. Products are grouped by strength (how hard they are to remove) and viscosity (how well they fill gaps).

How to use it

1. Choose the strength by how often the part must come apart.
2. Check the fastener size against the product's range.
3. Decide pre-applied or post-assembly. Wicking grades go on after the parts are tightened.
4. Clean and dry the threads. Use a primer on inactive surfaces such as stainless steel, zinc, plated parts or cold conditions, if the data sheet calls for one.
5. Allow the full cure time before loading the joint.

Selection chart

Colors and size ranges are trade conventions that most makers follow. They are not set by a standard. Always read the label.

Key points

• High strength means permanent in practice. Use it only where the part should not come apart in normal service.
• Removal heat and cure times vary by product. Get them from the data sheet.
• Threadlocker changes the friction on the threads. That can change the clamp load for a given tightening torque. Follow the fastener and adhesive makers' guidance.
• Threadlocker is not a substitute for proper bolt preload.
• Do not use on plastic parts unless the product is rated for them. Some anaerobics crack plastics.

Common mistakes

• Using red where blue was intended, then damaging the part on removal.
• Applying to oily threads without a cleaner or an oil-tolerant grade.
• Loading the joint before the adhesive has cured.

Governing standards: ASTM D5363 (anaerobic single-component adhesives); adhesive maker technical data sheets; fastener maker tightening guidance.

Reference only. Verify against the current governing code or standard, the manufacturer's data and the project documents before use. Apps for Distributors disclaims liability arising from reliance on this reference.