Threadlockers are used to prevent loosening caused by vibration, heat, and humidity. Threadlockers are applied to fastener threads to fill gaps and seal off imperfections in order to improve fastener performance. Aerobic threadlockers require air to dry and primarily act as a thread filler to stabilize joints. Anaerobic threadlockers do not require air to dry and cure to a solid form when exposed to metal ions in the absence of air. Some threadlockers offer permanent bonds while other threadlockers are removed by applying heat.