Loctite 290 Wicking Grade MIL-SPEC Medium-High Strength Green Threadlocker is a medium-strength wicking threadlocker for pre-assembled bolts up to 1/2". Penetrates threads by capillary action. Secures set screws and other assemblies after settings are completed. Seals welds and porous metal parts. Applications include instrumentation screws, electrical connectors and set screws and also seals porosities in welds and metal parts. Mil-S-46163A Type III, Grade R. NSF/ANSI 61 Certified.