Anaerobic Adhesives Reduce Costs and Increase Reliability for Industries

3rd September 2009

Source: Henkel

Whitepapers

Datasheet

Threaded fasteners set and hold tolerances on assemblies ranging from light duty equipment to heavy machinery. In many cases fasteners that self-loosen during equipment operation may contribute to wear and fatigue, and result in poor operating tolerances, misalignment, and sometimes catastrophic equipment failures that cost millions of dollars in unscheduled downtime each year. Various types of differential stresses such as vibration and shock, thermal expansion and contraction, and micro-movement reduce clamping force on the assembly and ultimately cause machine failure. Case after case, anaerobic threadlocking adhesive technology has proven to be more reliable and cost efficient to prevent the loosening of threaded fasteners and leakage in a variety of applications versus mechanical fasteners such as spring washers, wire retainers and nylock nuts.

Liquid threadlockers have become one of the most reliable and inexpensive ways to ensure that a threaded assembly will remain locked and leak proof for its entire service life. Applied drop-wise to fastener threads, liquid anaerobic adhesives fill the grooves of the threads and cure to a hard thermo-set plastic when exposed to active metal ions in the absence of air. Anaerobic adhesives lock the threaded parts together, ensuring that mating parts will ultimately act as one conjoined part that resists failure and delivers the greatest possible reliability.

Mechanical devices such as spring washers, wire retainers and nylock nuts are costly and are ineffective in preventing loosening of threaded fasteners caused by side sliding motion. They also do not seal or prevent corrosion within the fastener assembly and must be sized appropriately for the specific fastener, resulting in large and costly parts inventories.

Most assemblies held together by threaded fasteners will at some time be dismantled for repairs, maintenance or adjustment. For this purpose, industrial anaerobic adhesives are available in differing grades: low strength threadlockers for easy removal, medium strength threadlockers that can be removed using common hand tools and high strength or “permanent” threadlockers suitable for very demanding assemblies with minimal service requirements. Even the high strength threadlockers
can be removed with standard hand tools following direct exposure to 232 - 260°C (450-500°F) high temperatures for about five minutes.

New technological advances in anaerobic threadlocking adhesives have also provided many advantages previously unavailable including surface insensitive, high temperature, and chemically resistant
materials, as well as formulations engineered to withstand extreme vibrations. Semi-solid threadlocking formulations in a stick format that complement their liquid counterparts have also been developed to work well in overhead or hard to reach applications where liquids might be too messy or potential migration might be a concern.

Since its invention in 1953, liquid anaerobic threadlocking adhesives and thread sealants have become the most reliable and cost efficient methods for sealing and securing threaded fasteners and pipefittings in a variety of assemblies in many different industries. Many case studies have demonstrated that these innovative anaerobic adhesives and sealants are better able to withstand various types of differential stresses such as vibration and shock, wide range of temperatures and
micro-movements that reduce clamping forces than traditional mechanical threadlockers to reduce downtime, unscheduled maintenance and costs.