Loctite 290 Wicking Grade Medium-High Strength Green Threadlocker is a medium strength wicking threadlocker for pre-assembled bolts up to 1/2" (12 mm). Penetrates threads by capillary action. Secures set screws and other assemblies after settings are completed. Seals welds and porous metal parts. Mil Spec: Mil-S-46163A Type III Grade R. NSF/ANSI 61 Certified. Applications include instrumentation screws, electrical connectors and set screws and also seals porosities in welds and metal parts. Mil Spec (S-46163A) Type II, Grade M. NSF P1 Certified.