Anaerobic adhesives performance characteristics

Anaerobic adhesives are not generally stringy in nature and contain no solid catalysts, so they are suited for application on many relatively small parts -particularly co-axial assemblies where they can be placed with ease. Their characteristics ensure that they readily fill the minute gaps always found in interference-fitted joints. Thus, they can be used both to seal and supplement the overall performance of such joints. 

Figure 2.26 Postassembly thread locking. A high-strength, low viscosity anaerobic adhesive has been used to lock an M8 nut and bolt assembly. The adhesive was applied after the nut was tightened. Actual results obtained from a material to DTD 5633/Gl with a performance characteristic similar to pattern B in Figure 2.21.

Dayarante, K N., Dynamic performance characteristics of anaerobic adhesives. Project Report, Oxford Polytechnic, 1975. 

Note 3 Normally adhesives (non-anaerobic) are not assessed on collar and pin joints -but for comparison with the mechanical and anaerobic techniques the performance of several typical adhesives has been assessed using this method. Acrylic This type of toughened adhesive does not show up well on joints of this size because it is too compliant to be effective on small joint areas. On a large lap joint, a 50 per cent increase could be anticipated. Two-part epoxy The many formulations available could fall anywhere in the band indicated according to their individual characteristics. Single-part epoxy These toughened adhesives offer the maximum perform ance possible and are usually easier to use than two-part types. 

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