Soldering success is heat delivery, not heat temperature. The right tip, wetted and hot, at a moderate setting, beats a scorched needle at maximum. The iron transfers energy; you steer it.
At a glance: 6 minute guide · part 5 of 10 in the tools and equipment complete guide track · includes a worked example and a quick-reference table.
Choosing set-point and tip
Here is the working theory in one pass. 330–360 °C suits leaded work; 360–390 °C for lead-free. Tip geometry dominates: a chisel that bridges pad and pin delivers watts. A conical needle is a heat gate. Match tip size to the joint the joint should reach flow within two seconds.
| Work | Set-point | Dwell |
|---|---|---|
| Leaded through-hole | 330–350 °C | 1–2 s |
| Lead-free TH | 360–380 °C | 2–3 s |
| SMD with chisel | 340–360 °C | 1–2 s |
| Large pads/grounds | 370–390 °C + big tip | 2–4 s |
| Desolder braid | 380–400 °C | 2–3 s per pull |
The dwell-time rule
What this means at the bench. Heat both surfaces, feed solder to the joint (not the tip). Be done in 1–3 seconds for typical through-hole. Prolonged heating cooks flux and lifts pads. If joints need five seconds, the tip is wrong not the temperature.
Tip care economics
Tin the tip before every joint session, clean on a damp (not soaked) brass sponge, and re-tin before idle. Dry oxidation (“black tip”) kills wetting; tip-tinner resurrects it once. Tips are consumables budget accordingly.
How to apply this in your build
Work through the sequence below each step assumes the previous one passed. For numbers that need calculating, the linked tools at the end of this guide do the arithmetic instantly.
- Select the largest tip that fits the joint
- Set temperature for the alloy, not the folklore
- Clean and tin the tip before each work session
- Aim for 1–3 second joints adjust technique, not just °C
Worked example
Cold joints plagued a builder at “450 °C to be sure” with a needle tip. A 350 °C chisel flowed the same pads in a second the tip was the entire fault. Run the numbers yourself with the related calculator and the result should agree to within rounding.
Practical note from the bench. Bench rule: if the joint takes more than three seconds, change the tip, not the temperature dial.
Field mistakes we see again and again
- Conical micro-tips for regular joints
- Scrubbing the tip on abrasive destroying the plating
- Adding solder to the tip instead of the joint, starving the bond of flux
Key takeaways
- Choosing set-point and tip the foundation of this guide; revisit it if any measurement here surprises you.
- The dwell-time rule the foundation of this guide; revisit it if any measurement here surprises you.
- Tip care economics the foundation of this guide; revisit it if any measurement here surprises you.
Who this guide is for
Beginners get a single focused topic instead of a whole textbook chapter. It assumes the track’s earlier pages in the tools and equipment complete guide path. Intermediate readers use it as a reference the table, the worked example and the mistake list answer the questions that come up mid-build. If you teach, the structure (theory, application, example, failure modes) maps cleanly onto a lab session.
What you need before starting
Nothing exotic: the parts or tools named in the guide, a multimeter. A notebook for the numbers. Select the largest tip that fits the joint before you begin the guide assumes it and keep the quick-reference table above within sight while you work through the steps.
Quick reference card
| Aspect | Where to find it in this guide |
|---|---|
| Core theory | Choosing set-point and tip |
| Application steps | How to apply this in your build |
| Worked numbers | Worked example |
| Failure modes | Field mistakes we see again and again |
How this fits the tools and equipment complete guide track
This guide is one stop in the structured learning path. Start from the tools and equipment complete guide complete guide for the full map, or continue with SMD soldering and assembly defects.
Frequently asked questions
Higher temperature equals faster soldering? Up to a point; beyond it flux burns before the joint flows and pads pay. Tip geometry is the real throttle.
Wet sponge or brass wool? Brass wool is gentler and stays effective; sponges thermally shock tips slightly with every wipe.
Where do I go next? Back to the tools and equipment complete guide complete guide it indexes every guide in this track and updates as new ones are published.
Continue this track
- Building a foundation? The tools & equipment complete guide maps every step in order.
- Next: Hand Soldering SMD: Practical Techniques for Every Package
- Next: How to Use a Multimeter: Every Mode That Matters
- Next: Hot Air Rework: Removing and Replacing SMD Parts
- Work the numbers: frequency converter · trace width tool
Where to go next
- The complete tools & equipment guide: Tools & Equipment complete guide
- Read next: how to use a multimeter: every mode that matters
- Also in this track: oscilloscope triggering: the skill that makes waveforms stand still
- Continue with: probe compensation: the one-minute scope calibration
- Calculate as you go: frequency and wavelength tool · trace width calculator · resistor decoder
- Bookmark this page against the day a measurement surprises you. Most readers return to the table and the mistake list first, and that is the correct order.
Bench verification habits
When a result here disagrees with your expectation, write down both numbers before changing anything. The gap between predicted and measured is where the real engineering lives. It is usually a tolerance, a parasitic or an assumption that was never checked.
Keep a lab notebook entry for every build in this track. The measured values, the deviations from the guide and the reason for each. Six months from now, those notes are worth more than any tutorial. They describe your bench and your components rather than a general case.
Formulas and checks from this guide
Verification checklist for this track: compensate probes before trusting amplitudes, verify meter fuses before current work. Keep one known-good reference to sanity-check instruments. Calibration you can demonstrate beats calibration you assume.
Bookmark this page against your next build in the track. The checklist above is the same one used across 12 guides in this series.
From our lab notebook
After every move between scopes, and monthly as ritual. It costs one minute.
Warm-up drift is real in both. Swap in a known-good reference to decide which side drifts.
Last updated 23 August 2026