Kester 24-9574-7613 is a 1 lb spool, of lead-free, Ultrapure K100LD, no-clean, flux-cored solder wire with a diameter of .050 inches. It has a #66 core size and a 275 (no-clean) flux type.
Ultrapure K100 LD (is a lead free solder alloy):
Compares favorably to other low-cost, lead-free alloys of tin and copper in terms of wetting and flow characteristics.
Low cost, lead-free alloy
Bright, smooth solder joints with no visible shrinkage effects
Excellent through-hole penetration and topside fillet
Low dissolution of copper from boards and components into solder pot
20% Lower dross rate than SN63Pb37 in laboratory tests
Less corrosive to solder pots than SAC305
Kester 275 No-Clean (for lead bearing and lead free alloys):
Kester 275 No-Clean Flux for cored solder wire was developed to provide superior wetting performance for hand soldering in the electronics industry. The chemistry is based on some of the same principles that have been safely used for years in mildly activated rosin fluxes. The use of 275 no-clean flux results in an extremely clear post-soldering residue without cleaning. The unique chemistry in kester 275 was also designed to reduce spattering common to most core fluxes. Kester 275 can be used for both lead bearing and lead-free soldering.
Kester 275 Performance Characteristics:
Colorless translucent residues
Improves wetting performance
Excellent solderability and fast wetting to a variety of surface finishes
Eliminates the need and expense of cleaning
Low smoke and odor
Compatible with leaded and lead-free alloys
Classified as ROL0 per J-STD-004
Compliant to Bellcore GR-78
This product meets the requirements of the RoHS (Restriction of Hazardous Substances) Directive 2002/95/EC Article 4 for the stated banned substances. (Applies only if this core flux is combined with lead free alloy).