• Solder (धातु मिश्रधातु)

  • Flux (फ्लक्स – साफ और चिपकाने वाला पदार्थ)

Let’s understand both in detail.


🧪 What is Solder?

Solder is a metal alloy that melts at low temperature to join two metal surfaces. It provides a strong, conductive, and permanent bond between electrical parts.


🔧 Types of Solders

🧰 Type of Solder⚙️ Composition🌡️ Melting Point📝 Uses
Soft Solder (60/40)60% Tin + 40% Lead~180°CGeneral electrical wiring, circuits
Hard SolderBrass/Silver alloys400°C – 600°CMechanical joints, strong bonds
Silver SolderSilver + Copper/Zinc620°C – 660°CPrecision electronics, high strength
Lead-Free SolderTin + Copper/Silver215°C – 230°CEnvironment-friendly, electronics
Rosin-Core SolderTin + Lead + Rosin core~180°CElectronics (with built-in flux)

🧪 What is Flux?

Flux is a chemical substance used in soldering to:

  • Clean metal surfaces

  • Remove oxidation

  • Improve solder flow

  • Ensure a strong bond


🔬 Types of Flux

🔧 Type of Flux📋 Description🧰 Use In
Rosin FluxMade from tree resin, mild, non-corrosiveElectronics, PCB work
Acid FluxStrong cleaning agent, corrosivePlumbing, metalwork (Not for electronics)
Water Soluble FluxWater-based, easy to clean, mild to moderate actionElectrical circuits (cleaned after use)
No-Clean FluxLeaves minimal residue, no need to cleanModern PCBs, small electronics

🧠 Choosing the Right Solder and Flux

✅ Use rosin-core or soft solder for most electrical jobs
✅ Avoid acid flux in electronics – it can damage components
✅ For eco-safe work, use lead-free solder
✅ Always apply flux separately if using plain solder wire


⚠️ Safety Tips

  • Work in a well-ventilated space (flux fumes can be harmful)

  • Use eye protection when soldering

  • Always clean the joint after soldering (if using acid/water-soluble flux)

  • Store flux and solder safely and label them properly


🧠 Summary

🔍 Material✅ Key Point
SolderJoins electrical conductors using heat
FluxCleans and prepares surfaces for better bonding
Rosin FluxBest for electronics – safe and non-corrosive
Soft SolderMost common in ITI-level wiring and PCB work