Solder Melting Temperature | Work With the Right Temperature


Solder melting temperature is one of the most important aspects when you are manufacturing PCB Assembly.

At PCBMay, we know how critical the solder melting temperature is to producing reliable PCBs. Our skilled engineers and technicians are up to date on the most recent industry standards due to their years of expertise. It has cutting-edge technology to ensure your PCBs are put together precisely and correctly.

We employ high-quality materials and thorough quality control to guarantee that your PCBs have the greatest quality and dependability.

There is an ocean of knowledge floating around regarding soldering temperature. Our FAQ guide will clear most of your ambiguity regarding solder melting temperature. Let’s dive in.

In What Temperature Range Does Solder Melt?

Solder melting temperature is the point of temperature where the solder changes from one state to another, in this case, solid to liquid.

Overheating or underheating may cause the solder to melt or solidify unevenly, leading to a weak or nonexistent connection.

Soft solder’s melting point normally falls between 90 and 450 °C (190 and 840 °F; 360 and 720 K). The most typical melting temperatures for alloys are 180 and 190 degrees Celsius (360 and 370 degrees Fahrenheit; 450 and 460 degrees Kelvin).


How Much Pressure Can Solder Take?

The quality and composition of the solder contribute to the durability of a soldered bond. Soldering may hold up under mild loads, but it’s not always the best choice when you need a connection that can carry weight.

The pressure rating for a solder four-inch Type L junction is 440 pounds per square inch (psi). A joint’s rating drops to 293 psi if the field plumber brazes it instead of solders it.

The thickness, size, kind of solder, and quality of a soldered junction determine its pressure resistance. Generally, a soldered junction is strong enough to sustain hundreds of psi of tension.

Depending on the application and circumstances, soldered joints might vary in strength.

During vibration, shock, or torsion, soldered joints may break. If the solder cracks or breaks under these conditions, the solder’s conductivity and mechanical strength will decrease.

To avoid these problems, ensure the joint is well-anchored and supported, and lessen its loads.

Solder Pressure Test

Solder Pressure Test

How To Store Soldered Components?

The solder should be kept clean, dry, and dust-free to maintain its quality and function. Advice on how to safely keep solder on hand:

Keep solder away from heat and moisture

Solder may oxidize and get contaminated when exposed to moisture and humidity, resulting in subpar joints. Avoid storing solder in damp environments like basements or other places prone to water damage.

The solder should be stored in a cool, dark place out of the sun.

Solder may melt or become fragile if exposed to heat or sunshine, resulting in subpar joints. Keep solder out of the light and away from heat sources like radiators or heaters.

Keep solder in a sealed container

Airborne pollutants may pollute solder and cause subpar junctions to form. If you want to keep dust and other impurities from getting into your solder, be sure you keep it in a sealed box.

Store various solder kinds in a different container

Due to their distinct melting temperatures and chemical compositions, solder types should not be combined. Be sure to keep various solder kinds in separate containers and clearly identify them.

Solder should be dated and labeled

Exposure to external conditions like moisture or heat may cause the solder to corrode and lose its efficacy over time. Date stamping solder can help you keep track of when you bought it or when it was made.

Storing Soldered Components

Storing Soldered Components

How Do You Prevent Heat Damage When Soldering?

The solder joints can get damaged or even break if the temperature is too high. This can hurt the parts or materials that are being joined. When soldering, taking many important steps to protect against heat damage is important.

Ensure your soldering iron has enough power to do the job.

If the iron is too strong, it might make too much heat. You can also get equal heat distribution by using the right tip size for the job.

To ensure the heat is spread evenly, the soldering iron must be held at a 45° angle and turned in short circles. If you leave the iron in one spot for too long, it could get too hot and cause damage.

Also, heat sinks or materials that can handle high temperatures can be used to keep parts from getting too hot. By directing the heat away from the part being soldered, these materials help keep the part from melting.

During soldering, avoid parts that could be damaged by the heat, like capacitors.

Just as important as using the right tools and methods is taking breaks during long soldering sessions to let the iron cool down. If you do this, the iron won’t get too hot and hurt itself.

Lastly, you must have good soldering tools. But different solders have different melting points and require different amounts of heat, so choosing the right one is important.

Solder melts at 450 degrees Celsius

Solder melts at 450 degrees Celsius

What Is the Best Solder Diameter?

The solder’s diameter plays a major role in the joint’s durability, in addition to the job’s simplicity and precision. The solder diameter depends on the size and kind of components being connected, the soldering tool, and the solder’s competence.

Diameters of 0.6mm, 0.8mm, 1.0mm, and 1.2mm are the most used in electronics soldering. Solder diameter recommendations often need to be made in relation to the size of the parts being connected.

Surface-mount devices (SMDs) and other tiny electronic components benefit from using thinner-diameter solder, such as 0.6mm. This is because solders with a narrower diameter may more readily move across confined regions without bridging neighboring connections.

Solder with a wider diameter, say 1.0 or 1.2 mm, could be better suited for use with bigger parts. A bigger diameter solder can transmit more heat and fill greater gaps, making junctions stronger and more trustworthy. Too much solder might cause component bridging or shorts if the diameter is too thick.

The ideal diameter of the solder to use also depends on the soldering equipment being used. To attain precision and accuracy, a soldering iron with a small tip may need a thinner solder, whereas a soldering gun with a bigger tip may need a thicker solder.

What Are Solder Blends?

Mixed metals or alloys, known as solder blends, are used in soldering to form a solid weld between two metals. The blends can differ depending on your board and the metals you have.

Eutectic solder is a good pick since it combines two or more metals. Its melting point is significantly lower.  If you are regular in soldering, Eutectic solder is a great choice.

One more solder blend is flux-core solder. This cleans metal surfaces and prevents oxidation during soldering. When you heat it,  the flux core activates, eliminating oxides and strengthening the weld between the metals.

A solid joint silver-based solder blend can be a great choice. Silver’s high proportion in these mixtures makes for a strong connection between the metals being connected and good conductivity.

Solder Blend

Solder Blend

What Happens if the Solder Is Overheated?

If the solder gets too hot, it can damage the joint and your PCB in other ways.

At first, the solder gets too thin and runny. It makes the solder hard to control and increases the chance of short circuits or other damage. This can be a big problem when  soldering small parts or circuits with many connections.

In addition, if the solder is heated to high temperatures, it will lose its strength. It leads to connections that are either slack or weak. This may result in your electronic gadget being inoperable or fully broken, both of which need costly repairs or replacements if they occur.

Overheated solder

Overheated solder

If you overheat the solder and it contains lead, the fumes produced by the solder may harm your health if you breathe them in, especially if you overheat them. This is why ensuring enough airflow and wearing the right safety gear when soldering is important.

Overheating can also hurt the circuit boards, capacitors, and resistors that are being soldered. If there is too much heat, these parts can melt or get damaged, making them useless and possibly hurting other parts.

To avoid these issues, it’s important to solder at the right temperature and with the right techniques.

How to Check the Correct Melting Temperature for the Solder?

You can do a few things to check if your solder is melting at the right temperature. First, look at your specific solder blend’s technical specs or datasheet to find the advised melting temperature range.

Next, use a thermocouple or infrared thermometer to check the temperature of your soldering iron or another heating instrument.

Before you sell your parts together, testing the temperature and ensuring the solder flows evenly on a scrap piece of material is also a good idea. This will let you change the temperature if needed before you solder your parts together.

Keep an eye on the solder throughout the soldering procedure to make sure it flows properly and uniformly.

Checking soldering temperature

Checking the soldering temperature

How Long Does Solder Last?

There are a number of variables that affect how long a soldered junction lasts, including the material and method utilized to solder the parts together. A correctly soldered junction may survive years or decades, depending on the application and environment.

Properly stored performances have a life span of as long as five years. Lead-containing metals oxidize more quickly. Therefore, it’s best to utilize them after six months after production.

The durability of a junction is significantly affected by the caliber of the solder employed. Solder alloys of higher grade, devoid of impurities and contaminants, last longer and resist corrosion better than those of lesser quality.

When considering how long a soldered junction will last, it is equally necessary to consider the application method. To guarantee the solder sticks well and makes a strong connection, the joining surfaces must be thoroughly prepared by cleaning and fluxing. Solder junctions may be weak or fragile and eventually fail if they are overheated or underheated.

The longevity of the soldered junction might also be affected by the environment in which it is utilized. Solder may corrode or degrade over time due to moisture, temperature fluctuations, and other environmental variables. The joint might fail due to structural pressure, vibrations, or other physical causes.

What Is the Secret to Good Soldering?

Perfect solder joints may be achieved with the right technique involving expertise, patience, and attention to detail.

Successful soldering begins with thorough planning. This includes ensuring the joining surfaces are oxidation-free and other impurities that might prevent the solder from adhering. A soldering iron or gun, solder, flux, and a stand to store the iron are all necessary instruments.

The second key to successful soldering is using the correct solder.

The application, materials being bonded, and needed strength and durability will determine the solder type utilized.

Having the right technique is the third key to successful soldering. This requires heating the junction, applying solder at the optimum temperature and pace, and insuring that solder runs freely and evenly into the joint.

Overheating the junction or adding too much solder might cause the joint to become weak or brittle.

Good Soldering

Good Soldering

What Temperature Does 50-50 Solders Melt At?

The 50/50 Solder is made of 50% tin and 50% lead. A thermocouple or infrared thermometer can monitor your soldering iron’s temperature to keep it within the specified range.

About 183° Celsius is the melting point of fifty-fifty solder (361 degrees Fahrenheit). Because of its low melting point, it may be easily melted and put into electrical and electronic parts that don’t require as much heat.

Operating within the ideal temperature range while using fifty-fifty solder to achieve uniform melting and flow is essential. The solder should not be heated to the point where it melts since this may lead to poor connections.

Fifty-fifty solder is widely sought after, and not simply because of its low melting point. It has several potential uses, such as electrical wiring, plumbing, and repairing damaged circuit boards. Because of its low melting point, it may be used in situations where lower heat output is preferable, like while handling heat-sensitive components.

Although fifty-fifty solder is still widely used, it is important to remember that the lead it contains may harm human health and the environment.


50-50 Solder

50-50 Solder

What Factors Can Affect the Melting Temperature of Solder?

When working with solder, knowing that many things can change the temperature at which solder melts is essential.


When you heat solder, the metals mix to make a hot eutectic that wets the pad or the via. Once the heat source is removed, the solder cools into a convex “fillet” around the component’s edge due to surface tension.

Yet, if the solder is heated to a too-low temperature, the eutectic will not mix effectively and solidify as a cold junction. In other words, the solder joint won’t hold.

Because the eutectic mixture needed to be mixed better, a cold joint has a dull, craggy surface and is not very strong.

Joint size

Solder’s melting temperature can also be affected by the size and depth of the joint being made.

Flux type

The type and quality of the flux used with the solder can also affect the temperature at which it melts.

Flux and Oxidation

Even though most PCB assemblers aren’t chemists, it helps to understand the basics of the subject in order to realize the significance of solder flux. When soldering, molten solder produces a heated eutectic that interacts rapidly with oxygen to create oxides.

Compared to metals, metal oxides are weaker in terms of mechanical strength. Flux is also good because it helps eliminate any greasy leftovers in the area. When making a PCB, the right flux and the right amount of flux must be used with the right solder.

External Factors

Sadly, this is an external variable that cannot be changed. Higher temperatures and humidity may melt the solder at a lower temperature, whereas colder temperatures may need a higher temperature.

Are There Any Safety Precautions That Should Be Taken When Soldering at High Temperatures?

Safety precautions, such as when soldering, must always be followed while working with high temperatures. Hence, you must observe certain fundamental rules for your own protection.

First, when the solder iron’s tip reaches temperatures of 400 degrees Celsius, it is very dangerous to contact them. Second, you may avoid being burned by holding the wires with tweezers. Finally, to prevent the sponge from drying out and overheating, it is crucial to maintain it damp while in use.

Don’t forget to restore the soldering iron to its stand after each use. The stand should be sufficiently substantial, or the desk should be reinforced to prevent the stand from being moved.

While not in use, a gadget should always be powered off and unplugged. To prevent accidental damage to your circuit board or its components, using a soldering iron of the appropriate size is essential. Also, if you lose a soldering iron, you should never try to pick it up.

It is crucial to use eye protection while handling solder, flux, and cleaners. Cleansing solutions should also be kept in a sealed dispenser to prevent accidental inhalation.

Once you’re done soldering, wash your hands thoroughly with soap and water. As another precaution against harmful vapors, lead-free solder is strongly suggested.

Solder and flux emit toxic fumes that may be inhaled. Thus, it’s important to work in a well-ventilated location. The flux is the smoke’s main source, which irritates those with sensitive skin and may even worsen asthma symptoms.

Soldering Precaution

Soldering Precaution

If you’re working in an area where harmful vapors can be present, tilt your head to one side. The potentially harmful airborne byproducts of soldering, such as flux, may also necessitate using a tabletop fume extractor.

Always use caution while working with electricity, especially when soldering. Every electrical device should have a grounding prong and be plugged into a grounded outlet. No soldering should ever be done on a live circuit, and all electrical lines should be protected with insulation.

It’s safer to avoid starting a fire by doing your task on a non-flammable surface. Hot soldering irons may start fires. The soldering iron must be kept away from anything combustible. Use flame-resistant or cotton garments to prevent burns. Last but not least, everyone must know where a fire extinguisher is kept and how to use it in an emergency.


The melting point and other solder characteristics are vital to know when assembling electrical devices to ensure their reliability and quality.

Solders can make or break your electronic devices. So take care of all the considerations when you choose and do solder.

Here, we talked about different parts of the solder joint and how, if you practice, you can keep yourself and those around you safe.

At PCBMay, we provide our customers with a wide range of high-quality electronic manufacturing services, including soldering. Our skilled technicians use high-tech tools and follow strict quality control procedures to ensure that every part is soldered to the highest quality and reliability standards.

PCBMay is your one-stop shop for all your electrical manufacturing requirements.

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