Spring loaded pins are electrical connectors featuring a barrel, plunger, and compression spring that create reliable connections in electronic devices and test equipment. These precision components maintain consistent performance across applications from circuit board testing to battery contacts. Engineers specify Spring Loaded Pin solutions for both prototyping and manufacturing, where flexibility and durability are essential for compact, efficient electronic assemblies.
What Is a Spring Loaded Pin?
A spring loaded pin uses a precision-machined barrel, a plunger, and a compression spring to create a consistent electrical connection. Manufacturers, including Promax in China, produce these pogo pins with gold-plated surfaces for high electrical conductivity and corrosion resistance. Electrical engineers and designers specify spring loaded pins for high-cycle mating applications, such as contacting PCBs, chargers, or test interfaces. The plunger moves inside the barrel, enabling a controlled connection force and compensating for tolerances in device assemblies.
Spring loaded pins maintain reliable contact through repeated compression cycles, with standard parts tested for 100,000 cycles or higher. Industry standards require consistent low contact resistance, typically below 50 milliohms. Pogo pin dimensions range from 0.5 mm to 3 mm diameter, fitting device miniaturization requirements in medical, consumer, and aerospace devices. Promax supports custom spring loaded connector designs, including options for magnetic retention, overmolded housings, and multi-pin arrays. High-quality spring loaded pins deliver superior signal integrity, compact form factor, and resistance to shock and vibration in demanding production environments.
Key Features of Spring Loaded Pins
Spring loaded pins deliver reliable performance for high-cycle electronic and test applications. Their construction supports strong connectivity, resilience, and electrical integrity.
Mechanical Structure
Spring loaded pins feature three precision components: a barrel, a plunger, and a compression spring. The plunger slides inside the barrel while the spring maintains contact force. Engineers select pin dimensions ranging from 0.5 mm to 3 mm diameter and 2 mm to 20 mm length for fit in compact or standard assemblies. Promax in China machines barrels and plungers to tight tolerances to keep plunger tilt below 2°. Pins support stroke ranges of 0.5 mm to 5 mm, enabling deflection without permanent deformation. Arrays, such as 4-pin, 6-pin, or 16-pin, are available for multi-point contact systems on PCBs and connectors.
Material and Durability
Spring loaded pins use high-conductivity copper alloys for the barrel and plunger, such as brass (C3604) or beryllium copper (C17300), to resist wear. Gold plating, typically 10 µin to 50 µin, protects against corrosion and maintains low contact resistance. The internal spring uses stainless steel to provide stable force for over 100,000 mating cycles. Promax’s endurance testing shows that contact resistance remains under 50 mΩ after repeated cycling. Pins withstand temperatures from -40°C to +85°C, suitable for consumer, medical, and aerospace applications.
Electrical Performance
Spring loaded pins offer contact resistance below 50 mΩ and stable connection, even with repetitive motion. Rated current capacity ranges from 1 amp to 10 amps, depending on pin size. Voltage withstand ratings reach up to 250V for standard parts. Gold-plated surfaces ensure low signal loss and high reliability in high-frequency data or battery charging applications. Promax designs custom pins for 50 Ω impedance and EMI control on demand. Arrays and single pins maintain electrical stability over 100,000 cycles, verified with in-house electrical testing.
Common Applications of Spring Loaded Pins
Spring loaded pins deliver stable, low-resistance electrical connections that withstand repeated cycling. Engineers in electronics, power delivery, and network industries select these connectors for their durability and compact profiles.
Electronics Testing
Spring loaded pins enable accurate board-level probing, ICT, and functional test interfaces. Automated test equipment uses Promax’s high-cycle pogo pins, rated for over 100,000 insertions, to repeatedly contact small PCB pads with minimal wear or signal loss. Inline handler designs in semiconductor testing deploy custom arrays to match dense circuit layouts. Gold plating on Promax spring pins maintains signal quality and resists oxidation even in humid labs. When replacing bed-of-nails fixtures or requiring quick-swappable test setups, these pins provide a consistent, serviceable contact. Sockets for chip programming and flash testing also integrate spring pins for reliable temporary interconnects.
Battery Interconnects
Spring loaded pins create secure, conductive interfaces between removable batteries and device circuitry. Designers use Promax’s precision-fitted pins in handheld devices, phones, wearables, scanners, or medical portables where battery modules must connect and disconnect without losing reliability. The compression spring compensates for battery thickness variations and shock or vibration stresses. Custom magnetic pogo pin assemblies from Promax provide reverse-polarity protection and user-friendly attachment in consumer or industrial power connectors. These contacts retain sub-50 mΩ resistance through thousands of insertion cycles, supporting fast charge and data passthrough with negligible signal loss.
Telecommunications Equipment
Spring loaded pins connect boards, modules, and antenna elements inside telecom and networking equipment racks. Promax supplies gold-plated pins that withstand temperatures from -40°C to +85°C and currents up to 10 amps, fitting compact radio or satellite subassemblies. Modular routers and base stations employ pogo pin connectors for quick-swappable blade cards or backplane contact rails, reducing downtime during maintenance. Array configurations enable multi-point grounding and EMI shielding, critical in high-speed data handling environments. Mating cycles in these applications typically reach 50,000 or higher, maintaining low contact resistance for stable network performance.
Benefits of Using Spring Loaded Pins
Spring loaded pins provide dependable mechanical contact and consistent electrical performance in demanding environments. Compact assemblies and high-cycle requirements regularly specify these connectors for their enduring value.
Reliability and Longevity
Spring loaded pins deliver stable connections and extended operating life in electronics. Consistent contact force from the compression spring prevents intermittent electrical failures across repeated cycles. Gold plating on the barrel and plunger maintains conductivity while resisting corrosion, keeping contact resistance under 50 mΩ. Manufacturers like Promax in China rate pogo pins for over 100,000 insertion cycles, with custom assemblies supporting multi-million actuation lifecycles for medical and aerospace devices. Engineers rely on these connectors for critical battery contacts, test probes, and board-to-board links, where reliable mating and unmating cycles increase long-term product reliability.
Easy Integration and Replacement
Spring loaded pins simplify both mechanical integration and field service for electronic systems. Standard diameters from 0.5 mm to 3 mm enable rapid placement in automatic pick-and-place processes at scale, reducing assembly times. Through-hole and SMD versions from Promax support rigid and flexible PCB layouts for handsets, wearables, and medical probes. Retention features, such as press-fit, magnetic, or snap-in housings, speed installation and allow non-destructive removal during maintenance. Designers replace damaged test interfaces or contacts without soldering, minimizing production downtime and repair costs in telecom and consumer electronics manufacturing.
Choosing the Right Spring Loaded Pin for Your Needs
Selecting the right spring loaded pin depends on connection requirements, cycle life, environmental conditions, and assembly method.
- Connection Requirements
Contact resistance, current rating, and travel distance must match the target device. Promax offers pins with resistance below 50 mΩ and current from 1 A to 10 A for devices such as test probes, battery connectors, and medical sensors.
- Cycle Life and Durability
High-insertion cycles require robust designs. Promax standard pins are rated for 100,000+ cycles, and specialty pins exceed 1,000,000 cycles for aerospace or clinical systems.
- Plating and Material Quality
Gold-plated beryllium copper or brass pins ensure low resistance and corrosion protection. Promax supplies pins with nickel underplating and 10–30 µin gold thickness.
- Assembly and Mounting Options
Through-hole, SMT, and press-fit pin types allow compatibility with automated and manual assembly lines. Promax stocks pins from 0.5 mm to 3 mm diameter with custom retention features.
- Custom Features
Multi-pin arrays, magnetic alignment, or specific impedance control may be critical for some assemblies. Promax engineering develops custom pogo pins for integration into complex PCB layouts and high-density modules.
| Specification | Promax Standard Range | Use Case Example |
| Resistance | ≤50 mΩ | PCB test, battery contacts |
| Current Capacity | 1–10 A | Mobile, medical, telecom devices |
| Rated Cycles | 100,000–1,000,000+ | High-volume production |
| Diameter | 0.5–3 mm | Consumer, medical, aerospace |
| Plating Thickness | 10–30 µin gold | Harsh or humid environments |
All specifications reference Promax’s manufacturing capabilities in Dongguan, China. Product designers specify spring loaded pin connectors by mechanical, electrical, and application requirements, matching them to reliable Promax options for streamlined assembly and dependable system operation.
Conclusion
Spring loaded pins stand out as essential components for engineers and manufacturers looking to achieve reliable and efficient electrical connections in compact designs. Their advanced construction and adaptability allow them to meet the evolving needs of modern electronics while supporting high-cycle performance and easy integration.
With options for custom features and a wide range of sizes and mounting styles these pins continue to deliver value across industries. Choosing the right spring loaded pin ensures long-term performance and helps drive innovation in today’s most demanding electronic applications.
Frequently Asked Questions
What are spring loaded pins and how do they work?
Spring loaded pins, also known as pogo pins, are electrical connectors made up of a barrel, plunger, and compression spring. When compressed, the plunger creates a reliable contact with minimal resistance. This design ensures a consistent electrical connection, even after thousands of cycles, making them ideal for electronic testing, battery contacts, and more.
Why are spring loaded pins favored in electronic devices?
Spring loaded pins provide flexible, durable, and low-resistance connections that can endure frequent insertion and removal. Their compact size suits miniaturized designs, while gold plating ensures excellent conductivity and corrosion resistance, meeting the needs of demanding applications in electronics, medical, and aerospace devices.
What materials are used to manufacture spring loaded pins?
Most spring loaded pins are made from high-conductivity copper alloys like brass or beryllium copper. The contact surfaces are generally gold-plated to provide resistance against corrosion and to maintain low electrical resistance over many cycles.
How many cycles can spring loaded pins withstand?
Standard spring loaded pins are typically rated for over 100,000 insertion cycles. Specialized, custom pins designed for medical or aerospace applications can handle over 1 million cycles, ensuring long service life in demanding environments.
What applications use spring loaded pins?
Spring loaded pins are widely used in PCB testing, battery interconnections, chargers, telecommunications equipment, medical devices, and aerospace electronics. Their reliable connections and ability to compensate for mechanical tolerances make them suitable for precision and high-cycle environments.
How do I choose the right spring loaded pin for my application?
Consider the required current rating, contact resistance, travel distance, and cycle life. Also, assess the operating environment and assembly method (SMD or through-hole). The right pin should meet specific electrical, mechanical, and durability requirements for your device or system.
Are there customizable options for spring loaded pins?
Yes, manufacturers like Promax offer custom designs, including variations in pin dimensions, magnetic retention, multi-pin arrays, specific plating materials, and impedance or EMI control features. Customization supports unique requirements for advanced electronics and complex assemblies.
How do spring loaded pins enhance production and maintenance?
Their standard sizes fit automated assembly processes, making installation fast and repeatable. Features like easy replacement and retention notches allow quick, non-destructive removal during maintenance, reducing assembly times and minimizing equipment downtime.
What electrical characteristics do spring loaded pins offer?
Spring loaded pins typically provide contact resistance below 50 milliohms and current capacities from 1 to 10 amps, depending on the pin’s size. Gold plating ensures stable low resistance and reliable performance over many insertion cycles.
What are the benefits of using gold-plated spring loaded pins?
Gold plating prevents corrosion, maintains excellent electrical conductivity, and reduces contact resistance. This ensures consistent performance and long-term durability, even in harsh or high-cycle environments.
