Kester 63-0002-2372 NF372-TB 1 Gallon Halide Free Soldering Flux Kester NF372-TB is a zero-halogen no-clean low solids liquid flux designed to be used in wave and hand soldering processes. It can be used with both leaded and lead-free alloys. One of its best features is the ability to withstand long dwell times and high preheat temperatures needed in thick board assemblies. Sustained activity within the flux allows for good barrel fill in challenging applications such as reflowed copper OSP boards or with difficult to solder components. NF372-TB residues are minimal clear and non-tacky for improved cosmetics. NF372-TB is classified as ROL0 flux under IPC J-STD-004B. 63-0002-2372