Articles
November 25, 2024
The exact melting point of solder you are working with has important ramifications for your project. It’s critical to have a strong understanding of the melting point of solder before selecting or working with it.
In this article, we will provide an overview of the melting point of solder, how and why it varies and tips for effective and safe soldering.
On average, the melting points of solder ranges from 90°C to 400°C, but it can vary further depending on alloy composition and the type of solder. The melting point of solder can be determined more exactly if it’s a eutectic or non-eutectic material.
A eutectic solder is when the alloy the solder is composed of melts and solidifies at one single temperature point. For example, eutectic alloys made from 37% lead and 63% tin have an exact melting point and solidifying point of 183°C. This point does not range, or change in any way.
An exact melting point leads to advantages such as better liquid flow, high-quality solder joints, and no cracks forming in the solder as it solidifies. Eutectic solder is often made from more affordable materials than non-eutectic solder and has a shiny, chrome-like finish.
Comparatively, a non-eutectic solder has a temperature range where it begins to melt into a liquid. For example, non eutectic alloys made from 60% tin and 40% lead have a melting range of 183°C to 191°C. The material will start to melt at 183°C and will become a residue between 183°C to 191°C, before finally becoming a liquid when it’s heated to 191°C.
This makes non-eutectic solder perfect for applications where the alloys must not be fully liquid or solid. For instance, a professional such as a plumber can shape the solder in this state to create a watertight pipe.
Generally, eutectic and non-eutectic solders are placed into two categories: High temperature solder and low temperature solder.
Bromic offers rosin core electrical solder and acid core solder. Both of these types of solder have a melting point of 221°C.
When working with any kind of solder, be aware of potential safety hazards including eye and respiratory tract irritation, and take the necessary precautions.
Before melting soldering wire or paste with a welding iron or other tools like a gas torch, consider which type is best for your work. The difference between melting points in high temperature soldering and low-temperature soldering is due to the metals used in each kind of composition.
High-temperature solder is typically composed of mainly lead, with a lower percentage of tin than other solders. Lead-free high temperature solders use metals like gold or silver in their composition instead. The melting point of high temperature solder ranges can range from 221°C to over 950°C depending on the material and purpose of the soldering.
High-temperature solder is used in aerospace, automotive and heavy equipment industries. The material is durable and can be used to create long-term repairs of heavy machinery with a high-temperature point. This ensures the repaired device will be safe for use in high-temperature environments.
Low-temperature solder is made of tin that’s blended with other materials, such as cadmium, indium, bismuth or silver. The melting point of low temperature solder commonly ranges from 150°C to 170°C.
It is commonly used in assembling electronics or connecting electric components. Circuit boards and similar devices are heat sensitive, making low temperature solder ideal for attaching and connecting pieces.
Depending on your project, choosing the right solder can make a difference in how effective and efficient your application is within the project. The following are factors to consider as you choose the right solder for your project:
Are you working on car repairs or building a new circuit board? The application of your project isn’t just what the purpose of the project is, but the environment that the end product will ultimately be in.
Any solder used for electronics must have a melting point that doesn’t damage components but retains conductivity. Comparatively, if solder is used on a water pipe the alloy cannot contain any lead at all and must be water resistant.
Eutectic and lower temperature solders can be easier to work with, but are not as durable and reliable once settled into a solid. Consider the budget and time frame of your project and adjust the materials of your solder accordingly.
Lead-based solder is shock-resistant and flows well, making it easy to work with. However, lead exposure is harmful without high levels of safety measures. Lead-free solders have a higher melting point and can be more expensive and hard to work with.
However, the alloy mixture is typically non-hazardous and has more versatile uses. Consider the price and placement of your project. If it is lead-based, it cannot be in regular contact with people.
Flux is used to enhance the liquid flow of solder and make it ‘wet’ so it spreads more evenly across a joint. Flux cleans the joint and helps create a stronger solder bond.
There are multiple different types of flux for soldering and three are specifically available for electronic soldering: Water soluble, rosin-based and no-clean. Water soluble is the easiest to clean off, rosin-based flux offers good flow but must be cleaned thoroughly. With no-clean flux, the paste doesn’t have to be cleaned off, but some projects may still require all flux to be cleared.
Some fluxes use hazardous materials or are harder to clean, but provide better solder flow. Consider your safety gear and time to clean delicate electronics once the solder joint has formed.
Products like Bromic’s acid core and rosin core solder don’t require flux to work due to their core compositions. This can make them more convenient for certain applications.
The price of each type of solder can vary depending on the alloy compositions. Additionally, some materials will require more flux, different types of gas torches or irons, and longer timeframes to create a successful bond. Consider your project’s budget requirements and the exact purpose of your solder.
Soldering improperly can cause mild to severe injuries that leave permanent scars. It can also result in workplace fires, exposure to hazardous materials and more.
Some top tips for safe and effective soldering include:
Bromic offers a range of quality soldering tools, flux pastes and wire accessories. Whether your project calls for electric soldering or metal repairs, our staff can find the right solutions for you.
With over 40 years of experience in the gas and plumbing industry, Bromic are the experts in creating high-quality products for working professionals. Our staff has the knowledge you need for durable, high-calibre soldering.
Browse Bromic gas torches and soldering tools today to get the tools and expertise for quality soldering and more.
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