What Is Through Hole Technology (THT)? Components, Advantages, and Uses
- Harshit Shah
- 27 minutes ago
- 6 min read
When building electronic devices that demand long-lasting reliability, strong connections, and excellent power handling, through-hole technology remains a dependable choice. Despite the rise of surface mount components, THT still plays a significant role in industries where strength and durability matter more than miniaturization.
In this blog, we’ll explore what is a through hole, how through hole components are used, what sets through hole vs surface mount technologies apart, and why through hole PCB assembly still holds value in modern electronics manufacturing.
Key Takeaways
Through-hole technology (THT) assembly involves inserting components with leads into drilled holes on a PCB and soldering them to pads on the opposite side.
Common THT components include resistors, capacitors, inductors, transformers, connectors, and electrolytic capacitors.
THT is known for its mechanical strength, heat resistance, and suitability for high-stress applications.
THT is ideal for aerospace, military, transportation, industrial, and power electronics where durability matters most.
THT and SMT can be combined on a single board to balance reliability and component density.
While SMT dominates most consumer devices, THT remains important for prototyping, testing, and rugged hardware applications.
The future of THT involves selective use in specialized industries rather than complete replacement by SMT.
Table of Contents
What Is Through-Hole Technology?
Through-hole technology (THT) is a method used in PCB assembly where components with wire leads are inserted into drilled holes on a through-hole circuit board and soldered to pads on the opposite side. This creates a strong mechanical and electrical connection.
This technique has been around for decades and remains especially popular in high-reliability environments like aerospace, industrial automation, and automotive electronics. Its ability to handle stress, vibrations, and thermal expansion makes through-hole mounting the preferred method for many product manufacturers or OEMs.
Components Used in Through-Hole Technology
There are many types of through-hole components used in the THT assembly process, each designed for specific roles within electronic systems. Below are some of the most commonly used:
Resistors and Capacitors with Long Leads
Ideal for general circuit control and power regulation, these basic through-hole components are a staple in nearly every PCB design.
Inductors
Often used in power supplies and filters, inductors help manage voltage spikes and current flow, making them vital in energy management circuits.
Transformers
These are crucial in signal isolation and voltage conversion, especially in high-power systems. Through-hole transformers provide stability and consistent performance over time.
Connectors
Connectors used in through-hole mounting are built to withstand physical stress and repeated engagement, which is common in industrial and consumer electronics.
Electrolytic Capacitors
Known for their bulk capacitance, electrolytic capacitors are selected for high-power circuits where voltage regulation and energy storage are critical.
Unlike SMD components, through-hole components are generally larger and easier to work with manually. This also makes inspection and replacement more straightforward during prototyping or repair.
Key Characteristics of Through-Hole Technology
What sets through-hole technology apart are several defining features that make it attractive for specific use cases:
Strong mechanical bonds – The solder joints pass through the PCB, offering enhanced durability.
Great for high voltage and high current applications – Especially in power electronics, including motor controllers or power supplies.
Reliable in mission-critical systems- Widely used in military communication equipment, radar systems, aerospace navigation controls, and satellite electronics, where failure is not an option and long-term reliability is non-negotiable.
Good for prototyping – Thru holes allow easy component swapping during design validation.
Supports manual and automated soldering – Making it flexible for small and large-scale production.
These characteristics of through-hole assembly make it a preferred method for engineers focused on durability and longevity.
What are the Advantages of Through-Hole Technology (THT)?
There are many advantages of through-hole technology, especially when reliability and ruggedness are top priorities:
Durability
The components are anchored with solder through the board, resisting mechanical stress and environmental wear.
Easy Prototyping
Engineers can easily swap out through-hole components during testing phases without damaging the board.
High Power Capability
Ideal for circuits that carry substantial currents or require robust connections.
Stronger Connections
Combining THT and SMD for your PCB assembly allows for hybrid designs that optimise for both reliability and board density.
Versatility
From single boards to complex PCB assemblies, THT technology supports a range of configurations and needs.
Cost Effectiveness
Through-hole mounting can reduce rework and long-term failure costs, especially in low-to-mid volume production runs.
Lead Times
THT offers stable production timelines, especially for industries that need consistent delivery without complex part placement.
What is Through-Hole Technology Used For?
While surface mount and through-hole methods are often combined in modern PCBs, through-hole technology continues to shine in several industries:
Military and Aerospace – Used in avionics control units, missile guidance systems, and military-grade communication devices, where components must survive shock, vibration, and temperature extremes.
Automotive Electronics – Found in engine control units (ECUs), airbag systems, and anti-lock braking systems, where vibration resistance and long-term reliability are non-negotiable.
Power Electronics – Applied in power converters, transformers, UPS systems, and motor drives, benefiting from strong electrical and thermal connections.
Audio Equipment – Utilized in amplifiers, mixers, and studio-grade sound systems, where heat dissipation and analog signal integrity are key for optimal performance.
These through-hole applications demonstrate the ongoing value of THT in the modern electronics ecosystem.
What is the Difference Between SMT and Through-Hole Technology?
The debate of SMT vs THT boils down to application-specific requirements. Here’s how they differ:
Size – SMT (Surface Mount Technology) supports smaller, denser designs. THT is bulkier but stronger.
Assembly Speed – SMT is faster and often fully automated. THT can be slower due to manual steps.
Durability – Pin through-hole mounting provides greater strength under stress.
Cost – SMT usually costs less for mass production, while THT may be more expensive but more robust.
In essence, the THT vs SMD choice depends on the goals of your product—miniaturization vs reliability. If you want to understand detailed differences, read our detailed blog on Surface Mount Technology vs Through Hole.
What is the Future of Through-Hole Technology?
Despite the miniaturization trend in electronics, through-hole technology is not disappearing. Its role is simply evolving.
In high-reliability applications, THT remains a trusted method. Through-hole PCB assembly will continue to serve industries where performance, strength, and longevity matter more than compact design.
Additionally, hybrid approaches combining surface mount and through-hole components are becoming more common, offering the best of both technologies.
Expect THT components to retain importance in prototyping, industrial controls, and anywhere rugged performance is required.
Conclusion
In a world dominated by surface-mount components, through-hole technology stands strong. It continues to be the go-to method for engineers building products that must endure extreme conditions, high power, and long operating life.
Understanding the strengths of through-hole components, the advantages of through-hole, and how through-hole soldering supports product integrity allows manufacturers to make smarter choices in design and production.
If you're building a product that needs rock-solid durability, through hole might be exactly what your project demands. Get in touch with us to know how we can help build your projects.
Frequently Asked Questions (FAQs)
Q1. What is through-hole mounting in PCB assembly?
It’s a method where component leads are inserted into drilled holes on the PCB and soldered on the opposite side for a strong bond.
Q2. How does through-hole soldering differ from SMT soldering?
Through-hole soldering goes through the board, while SMT is mounted directly on the surface using reflow techniques.
Q3. What are the main advantages of THT?
It offers strong mechanical support, better heat resistance, and is ideal for high-power and high-stress environments.
Q4. Can THT and SMT be used on the same PCB?
Yes, combining both allows designers to balance durability (THT) and space-saving (SMT) needs.
Q5. What industries still use through-hole technology?
Aerospace, military, transportation, industrial, and power electronics still rely on THT for reliability.
Q6. Is surface mount better than through-hole?
SMT is better for compact, high-volume builds, but THT is stronger and more durable.
Q7. Is SMD soldering better than through-hole?
SMD soldering is faster and smaller, but through-hole is better for durability and power.
Q8. What are the applications of through-hole technology?
Through-hole technology is widely used in engine control modules, aerospace communication boards, high-voltage regulators, and factory automation systems, where durability, stability, and resistance to vibration are non-negotiable.
