IS 440 covers flux-cored solder wire for electronic and electrical soldering. Covers both traditional tin-lead (Sn63/Pb37) and modern lead-free (SAC305) formulations. The flux core provides cleaning action during soldering.
Specification for flux-cored solder wire used for soldering electronic, electrical, and plumbing joints.
Key Values
Sn63/Pb37 melting point183°C
SAC305 (lead-free) melting217-220°C
Common diameters0.5, 0.8, 1.0, 1.2mm
Practical Notes
! Sn63/Pb37 is the eutectic composition — sharpest melting point, best for hand soldering.
! Lead-free solder (SAC305) is mandatory for EU (RoHS) export products. Use for new electronics designs.
! Flux residue from rosin-core solder is non-corrosive and can be left on. Acid-core flux must be cleaned.