Weicon WEICONLOCK® AN 305-42 Anaerobic Thread Sealant 50 ml is an anaerobic industrial adhesive designed to provide sealing and medium-strength locking in pipe and threaded connections. In hydraulic and pneumatic lines, it helps reduce leak risk by filling thread gaps and offers a strength profile that allows disassembly with standard hand tools. Thanks to its medium viscosity, it spreads in a controlled way on threads and shows low tendency to run during application. It is manufactured in Germany by WEICON GmbH & Co. KG.

Hydraulic and pneumatic thread sealing with AN 305-42
This industrial adhesive belongs to the “pipe and thread sealant” class, developed specifically for sealing pipe threads and fittings. The technical description states suitability for threaded connections up to M20 and for pipe threads up to R 3/4″, helping maintenance and assembly teams use it across a broad range of connections. Its brown color and fluorescent property support visual control of the applied area. Having DVGW approval is an important indicator of standards compliance for certain application fields.

Performance features and technical limits
AN 305-42 has a viscosity of around 500 mPa·s, providing a medium-flow industrial adhesive character and aiming to form a uniform film on threads. Since the maximum gap-bridging value is given as 0.15 mm, it targets reliable sealing on properly toleranced metal threads. Positioned as a medium-strength grade, the “breakaway” torque is stated as 12–15 Nm and the “prevailing” torque as 18–22 Nm; this helps the connection remain more stable under vibration while keeping removal feasible with standard hand tools. Temperature resistance is specified as -60 °C to +150 °C, supporting performance continuity under variable conditions typical in hydraulic/pneumatic equipment.

Anaerobic curing principle and surface preparation
The product is a single-component anaerobic system that cures where oxygen is excluded between metal surfaces, creating a sealing effect. For best results, it is recommended that parts are degreased and clean; the cleaner the surface, the more consistent the sealing and locking performance. Nevertheless, it is stated that it can be used even on as-delivered screws in the field, but in such cases results may vary depending on surface contamination. Achieving initial strength within 10–20 minutes at room temperature and reaching final strength within 2–4 hours provides a practical time window for maintenance planning.

Application method and practical tips
In application, the product is applied evenly onto the thread in circular movements using the dosing nozzle, and the pipe thread is tightened and aligned to the desired position. When flange sealing is required, it is applied as a continuous bead to one side of the flange surface, then the parts are quickly joined and tightened. It is recommended not to let the dosing nozzle directly touch metal and not to pour product that has contacted metal back into the bottle, as metal particles can cause unwanted curing inside the packaging. Since a minimum shelf life of 24 months at room temperature is stated, storage away from heat sources and direct sunlight is important.

Industry applications and key advantages
This industrial adhesive can be used to meet thread-sealing needs in hydraulic power units, pneumatic lines, valve and manifold connections, compressor installations, and general machine maintenance processes. In automotive and heavy-duty maintenance, it supports leak control in oil circuits, compressed air connections, and threaded joints that are frequently disassembled and reassembled during service. In process industries, it can help speed up installation in line connections, at points where additional gasket support is needed on flange surfaces, and during equipment overhauls. Its medium-strength locking approach is a clear advantage for applications seeking to balance both sealing performance and serviceability. Being classified with ISSA and IMPA codes can provide easier tracking in corporate maintenance/cleaning and procurement processes.