Looking for a plug that will mask internal threads AND the first / lead-in thread during powder coating, ecoating, etc.? Check out these first thread plugs.
Thread, Silicone Masking Plugs
How To Mask Threaded Holes Before Powder Coating - Echo Supply
Masking caps & plugs
The Ultimate Guide to Caps and Plugs
First Thread Silicone Rubber Masking Plugs
Buy Silicone Tapered Plugs & Bungs Online, 1-127mm - Vital Parts
Silicone Caps - Masking
Silicone caps resistant up to 315 °C. Recommended for powder coating, E-coating, anodizing, plating and galvanic processes. Useful for pins and thread
Caps with flange for holes, pins and threads. Silicone made
Plumbing Plumber White 17mm Width PTFE Thread Seal Tape
High Temperature Caps & Plugs for Masking, Buy Online
DIY RTV silicone rubber uses for backpacking gear - Tim Tinker
Masking caps & plugs
20pc Extra Large High Temp Silicone Rubber Plug Kit
Silicone plugs resistant up to 315 °C. Recommended for powder coating, E-coating, anodizing, plating and galvanic processes. Thanks to the shape plugs
Hollow plugs with handle for thread protection. Silicone made