Anodizing processes expose masking components to sulphuric acid baths, chromic acid, or alkaline pre-treatment stages. Standard catalogue plugs may not maintain a consistent seal under these chemical conditions, or may degrade over repeated immersion cycles, leading to anodizing of surfaces that must remain bare metal.

Our custom silicone masking plugs for anodizing are moulded to your exact geometry and manufactured from silicone grades that resist the acid chemistry of standard anodizing baths. Each plug is designed for secure retention through immersion and clean removal without residue on critical surfaces.

All custom plugs are produced with a smooth outer surface to ensure consistent sealing against the masked surface. For applications involving threaded openings, custom threaded silicone plugs are available to protect thread geometry and provide a watertight seal through the anodizing process.

Key properties and configurations:

• Acid and chemical resistant: suitable for sulphuric acid anodizing baths, chromic acid processes, and alkaline pre-treatment stages
• Customisable hardness: Shore hardness selectable to match compression fit, retention under immersion, and sealing performance for each application
• Any geometry: tapered, straight, flanged, pull-through, threaded, and complex non-standard profiles available to drawing or sample
• Reusable and durable: high-quality silicone construction supports repeated use across multiple anodizing cycles without degradation of fit or chemical resistance
• Colour-coded to specification: any silicone colour available to support operator identification and process control
• Economical for small series: custom tooling is viable even for smaller quantities where no standard masking plug provides a reliable fit for your component

Lead time is typically 3 to 4 weeks from approved geometry.