Kester 44 Rosin Core Solder 63/37 .031" 1 lb. Spool

Kester 44 63/37 rosin-core solder, .031-inch wire, 1 lb spool

Kester 44 is an activated rosin-core solder wire for electronic and electrical soldering. This listing is for one 1 lb spool of 63/37 tin/lead solder with a .031-inch wire diameter. It is lead-containing solder, not a lead-free alloy. The 44 flux formulation provides fast wetting to help solder flow onto properly prepared connections.

Check suitability before ordering

For audio cable and connector assembly, confirm that the connector uses solder termination and follow its assembly instructions. Match your soldering process to the terminal, conductor size, plating and insulation; this spool is solder material, not an assembled cable or a cable-building service. If your project requires a lead-free alloy, choose a different solder.

Kester 44 is offered in multiple alloys, wire diameters and flux-core sizes. Those family options are not all included in this listing. A specific flux percentage is not stated here; check the spool label or manufacturer documentation if it is important to your process.

Soldering guidance

Heat the connection surfaces with the iron before feeding solder onto the joint. Avoid prolonged heating that can damage connector insulation or cable jackets, and inspect the finished connection for wetting, solder bridges and stray strands. Complete the connector's strain relief and test the finished assembly.

The listed process guidance gives common iron-tip temperatures of 315–343°C (600–650°F) for leaded alloys. This is process guidance, not a universal temperature setting or equipment limit. Follow the component instructions and adjust for your tools and joint. Additional liquid flux should be used only when needed; the listed compatible rework fluxes are Kester 186 and NF372-TB.

Features

• 63/37 tin/lead alloy.
• .031-inch wire diameter.
• One 1 lb spool.
• Kester 44 high-activity RA rosin flux formulation.
• Fast wetting and spreading action.
• Excellent solderability across a wide range of metallizations.
• Flux classified as ROM1 under IPC J-STD-004.
• Listed passing surface-insulation-resistance tests at 85°C/85% RH and 40°C/90% RH.

Flux residues and cleaning

The listed manufacturer guidance states that residues do not require removal for most applications under normal conditions of use. This is not a blanket guarantee for every circuit or environment. Follow your assembly's cleanliness requirements and Kester's guidance when residue removal is required.

The listed guidance says IPA will not remove these residues. Use a suitable saponifier or cleaning agent recommended for the flux and assembly materials, and consult Kester Technical Support for cleaning-process selection.

Listed flux reliability data

• Copper mirror corrosion: Moderate; IPC-TM-650 method 2.3.32.
• Corrosion test: Moderate; IPC-TM-650 method 2.6.15.
• Silver chromate: Fail; IPC-TM-650 method 2.6.33.
• Chloride and bromides: 0.44%; IPC-TM-650 method 2.6.35.
• Fluorides by spot test: Pass; IPC-TM-650 method 2.6.35.1.
• Surface insulation resistance at 40°C/90% RH: Pass; IPC-TM-650 method 2.6.3.7.
• Surface insulation resistance at 85°C/85% RH: Pass; IPC-TM-650 method 2.6.3.3, listed conditions of 7 days and 100 V.

These are flux test results under the stated methods, not a guarantee of finished-joint performance in every application.

Storage and handling

Store in a dry, non-corrosive environment at 10–40°C (50–104°F). The wire surface may become dull gray without affecting functionality. The listed shelf-life guidance for this alloy is three years from manufacture; this is not a statement of the manufacture date or remaining shelf life of current stock.

Read the product warning label and Safety Data Sheet before handling or use. Manufacturer documentation is available through Kester.

CALIFORNIA PROP 65 WARNING: This product can expose you to chemicals including lead which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.