For most electronics, set your soldering iron to 330 to 350°C for leaded solder and 350 to 400°C for lead-free. Drop to around 300 to 320°C for fine SMD and heat-sensitive parts, and go up to 380 to 410°C for large joints, ground planes and thick wire. The full chart and the reasons behind each setting are below.
Quick reference
Leaded solder: 330 to 350°C. Lead-free: 350 to 400°C. Fine SMD: 300 to 320°C. Large joints: 380 to 410°C. Always start at the lower end and raise the temperature only if the solder will not flow. You need a temperature-controlled iron or station to set these accurately.
Soldering Iron Temperature Chart
Use this chart as your starting point, then fine-tune for your solder and joint. Temperatures are tip temperatures in degrees Celsius.
| Job or solder type | Tip temperature | Notes |
|---|---|---|
| Leaded solder (63/37, 60/40), general electronics | 330 to 350°C | Melts around 183 to 190°C. The easy, forgiving choice. |
| Lead-free solder (SAC, Sn99.3/Cu0.7) | 350 to 400°C | Melts around 217 to 227°C, needs more heat and wets less easily. |
| Fine SMD and heat-sensitive parts | 300 to 320°C | Small thermal mass. Work quickly with a fine tip. |
| Through-hole and medium joints | 350 to 380°C | Headers, connectors, most general assembly. |
| Ground planes, thick wire, large connectors | 380 to 410°C | Big heat sink, needs more heat fast. |
| Desoldering | 360 to 400°C | Enough heat to reflow the whole joint at once. |
These are starting points, not hard rules. Tip size, solder, and how big the joint is all shift the ideal a little. The skill is using the lowest temperature that still flows cleanly.
Why Soldering Temperature Matters
The goal is to heat the joint enough for the solder to flow and bond, without cooking the part or the board. Getting it wrong shows up fast:
- Too cold: the solder will not flow properly, you get dull, lumpy “cold joints” that crack or fail to conduct. You also end up holding the iron on the board too long trying to make it work, which paradoxically applies more heat.
- Too hot: you burn the flux before it can clean the joint, oxidise the tip, lift copper pads and damage heat-sensitive components like ICs and electrolytic capacitors.
The right temperature lets you make the joint in one to three seconds, in and out, which is gentler on everything than a lower temperature held for longer.
What Temperature for Leaded Solder?
Leaded solder (63/37 tin-lead, or 60/40) melts at about 183 to 190°C, but you set the iron higher so heat transfers quickly into the joint. For general electronics, 330 to 350°C is the sweet spot. Drop to 300 to 320°C for delicate parts, and nudge up toward 360 to 370°C only for larger joints.
Leaded solder is the most forgiving to work with, which is why it is recommended for beginners. See the difference between alloys in our soldering wire range.
What Temperature for Lead-Free Solder?
Lead-free solder (SAC alloys, or Sn99.3/Cu0.7) melts higher, around 217 to 227°C, and does not wet as freely as leaded, so it needs a hotter iron. Set 350 to 400°C, typically around 370 to 390°C for general work. Larger joints can need the top of that range.
Lead-free wears tips faster
Because it runs hotter, lead-free is harder on tips. Keep the temperature only as high as you need, tin the tip well, and clean it often to make tips last. See how to clean soldering iron tips.
SMD, Copper and Other Special Cases
Fine SMD work
Surface-mount parts have a tiny thermal mass and sit close together, so use a lower temperature, around 300 to 320°C, with a fine tip and work quickly. Too much heat tombstones small parts and damages pads.
Soldering to copper
Copper pads and wires are what most electronics solder bonds to, and they take heat well, so the standard settings above apply: 330 to 350°C leaded, 350 to 400°C lead-free. Larger copper areas (ground planes, thick copper wire) pull heat away fast, so move to 380 to 410°C. Note this is electronics soldering, not copper plumbing pipe, which uses a blowtorch instead of an iron.
Large joints and thick wire
Big connectors, battery tabs and heavy-gauge wire act as heat sinks. Raise the temperature to 380 to 410°C and use a larger chisel tip so the iron can deliver enough heat before the joint cools the tip down.
How Hot Does a Soldering Iron Get?
A temperature-controlled soldering iron or station typically adjusts from about 200°C up to 480°C, though you rarely need the top end. Most electronics work happens between 300 and 400°C.
A cheap fixed-temperature iron has no control and simply runs as hot as its element allows, often somewhere between 350 and 450°C, which is one reason it is poor for electronics: you cannot dial it back for sensitive parts. That control is exactly what a soldering station gives you.
How to Set and Check Your Temperature
- Start low. Begin at the lower end of the range for your solder and only raise it if the solder is not flowing within a couple of seconds.
- Watch the joint, not the dial. A good joint flows out shiny and concave in one to three seconds. If it takes longer, add heat; if the flux smokes off instantly, you are too hot.
- Keep the tip tinned. A clean, tinned tip transfers heat far better, so you can work at a lower set temperature. A dirty tip behaves as if it is too cold even when the dial is high.
- Match the tip to the job. A bigger tip delivers more heat at the same temperature, often a better fix for stubborn joints than cranking the dial. Browse soldering iron tips.
- Verify if it matters. Station readouts can drift over time. A cheap tip thermometer confirms the real tip temperature if you need accuracy.
New to setting temperature at all? Our best soldering station for beginners guide covers controlled irons that make this easy.
Frequently Asked Questions
What temperature should a soldering iron be?
For general electronics, 330 to 350°C with leaded solder and 350 to 400°C with lead-free. Use 300 to 320°C for fine SMD and heat-sensitive parts, and 380 to 410°C for large joints and thick wire. Start low and raise only if needed.
What temperature for leaded solder?
Around 330 to 350°C for general work. Leaded solder (63/37, 60/40) melts at about 183 to 190°C, but the iron is set higher so heat moves quickly into the joint. Drop to 300 to 320°C for delicate parts.
What temperature for lead-free solder?
Around 350 to 400°C, usually 370 to 390°C. Lead-free melts higher (217 to 227°C) and wets less easily, so it needs a hotter iron than leaded solder.
How hot does a soldering iron get?
A controlled iron or station ranges from about 200°C up to 480°C. Most soldering is done between 300 and 400°C. A fixed-temperature iron runs uncontrolled at roughly 350 to 450°C.
What temperature for SMD soldering?
Lower than through-hole, around 300 to 320°C with a fine tip, working quickly. Small surface-mount parts have little thermal mass and are easily damaged by excess heat.
Is a higher soldering temperature better?
No. Hotter is not better. Excess heat burns flux, oxidises the tip, lifts pads and damages components. Use the lowest temperature that lets the solder flow cleanly in a couple of seconds.