Kester 04-9574-0050 K100LD  is ROHS, Lead-Free, Ultrapure Bar Solder.

• Lead-free wave soldering processes tend to produce a greater amount of dross than traditional leaded processes. For this reason, Kester produces all lead-free bar solder products with anti-drossing technology to improve process control and to allow the user to get the most value for the money with minimal maintenance costs. Kester Ultrapure SAC305 Bar Solder was designed to minimize the amount of dross generated in a wave soldering, selective soldering or dip soldering process. Kester Ultrapure SAC305 is manufactured with virgin metals which meet the high standards of Kester Ultrapure line of bar solders.
• K100LD: In response to demand for a low cost and low copper dissolution alloy, Kester has developed Ultrapure K100LD. Kester K100LD is a eutectic Tin/Copper alloy with controlled metallic dopants to control the grain structure within the solder joint, and to minimize the dissolution of copper into the solder pot. K100LD virtually eliminates the occurrence of common defects such as icicling and bridging. The improved grain structure also results in shinier solder joints than traditional lead-free alloy alternatives.
• Diminish the 5D's: Dissolution.  Dullness.  Defects.  Dross.  Dollars.
• K100LD / LEAD-FREE ROHS Compliant Solder
• K100LD is a new patent-pending low-cost lead-free solder alloy for use in wave soldering, selective soldering and tip tinning operations. K100LD has the Lowest Copper Dissolution amongst all common solder alloys, including SN63, SAC305, and other lead-free options. Kester K100LD provides the lowest cost for wave soldering operations. It also provides solder joints with no shrinkage effects, excellent through-hole penetration, topside fillet, and provides a low dross rate.
• K100LD has a melting temperature of 227 degrees C / 441 degrees F for a wave / hand soldering application