Lead-Free vs. Leaded Solder: Which Should You Use?

One of the first choices a new solderer faces is which solder to buy. The short answer: for learning, leaded is easier; for safety and compliance, lead-free wins. Here’s how to decide.

What’s the difference?

• Leaded solder is usually a 60/40 or 63/37 tin-lead alloy. It melts at a low temperature, flows beautifully, and forms bright, shiny joints — which also makes it easy to see when a joint is good.
• Lead-free solder is typically a SAC alloy (tin, silver, copper). It melts hotter, flows less eagerly, and tends to leave a duller, grainier-looking joint even when it’s perfectly sound.

Melting point and ease of use

Because lead-free runs hotter and wets less, it punishes a weak technique more. That’s the main reason it’s harder to learn on. A good temperature-controlled station helps a lot with lead-free.

Safety and regulations

Lead is toxic, so the obvious advantage of lead-free is no lead exposure — relevant for children, food-contact items, and products sold commercially. The RoHS directive requires lead-free solder in most consumer electronics sold in the EU and many other markets.

That said, both solders release flux fumes when heated. Those fumes — not the lead — are what you’re breathing at the bench, so ventilation and washing your hands after soldering matter no matter which you choose.

So which should you buy?

• Learning at home, by yourself? Leaded 60/40 (0.6–0.8 mm) is the gentlest way to build technique. Wash your hands and ventilate.
• Soldering with or for kids and teens, or building something others will handle? Choose lead-free.
• Building products to sell, or in a RoHS region? Lead-free is required.

Whatever you pick, get thin, rosin-core solder so flux is built in, and pair it with the right iron and a practice kit. Then work through our beginner soldering guide.