Coiled Spring Pin!? What the heck is that?

Welcome back to our “what the heck is that” series, where we discuss some of the unique fasteners and electronic hardware that manufacturers use in the design and assembly of their products. Today, we will introduce you to the Coiled Spring Pin! This mighty Non-Threaded Fastener, AKA Spiral Pin or Coiled Pin, is small in size, but it offers remarkable effectiveness in fastening and securing a wide range of components. The coiled structure of this fastener grants it flexibility and resilience, which in turn enables it to absorb shock, vibration, and lateral forces effectively. In general, this fastener is self-retaining, and will stay in place once installed;. This eliminates the need for additional retaining devices, simplifies the assembly process, and can reduce overall costs.

What are Coiled Spring Pins?

Also known as Spiral Pins or Coiled Pins, Coiled Spring Pins are headless & hollow pins with chamfered ends. They are usually made by shaping or wrapping a steel sheet into a slightly larger diameter than the standard size. This, in turn, results in a coiled design that allows them to distribute forces evenly along their entire lengths, mitigate stress concentration at specific points, and diminish the likelihood of component failure or fatigue when in use.

These pins are frequently used to join and fasten two or more components together. When the pins are inserted into pre-drilled holes, their spiral shape allows them to expand and exert radial pressure against the sides of the hole, which in turn creates a precise and secure connection. This is particularly crucial in applications subject to constant movement, such as machinery and automotive systems.

The versatility, ease of installation, and distinctive design distinguish Coiled Spring Pins from other pins in the same category. This is because, apart from their fastening functionalities, these pins can also serve as effective retaining features. They have the ability to secure various items, such as gears, pulleys, or bearings, onto shafts, effectively preventing axial movement or slippage. Hence, whether utilized in machinery, automotive systems, electronics, or countless other applications, Coiled Spring Pins excel in delivering dependable, long-lasting, and cost-effective solutions.

Who uses Coiled Spring Pins?

Due to their dependable nature and versatility, Coiled Spring Pins are extensively utilized across various industries and applications. Here are some of the industries where coiled spring pins are commonly used:

  • Aerospace Industry: In the aerospace industry, Coiled Spring Pins play a vital role in applications that require reliable fastening and long-lasting durability. They are utilized in aircraft structures/frameworks, electronic components, circuit boards, landing gear, engines—where Coiled Spring Pins play a crucial role in guaranteeing the secure attachment of vital components like turbine blades, compressor parts, and fuel system components—and other crucial systems. These pins demonstrate excellent resistance to vibration, fatigue, and extreme temperature variations, making them highly suitable for demanding aerospace applications.
  • Automotive Industry: Coiled Spring Pins are an integral part of the automotive industry. These pins are used in critical components such as brake systems, engine assemblies, transmissions, suspension systems, etc. Their exceptional capability to withstand high forces, resist loosening due to vibrations, and deliver dependable connections makes them highly suitable for the rigorous demands of automotive environments.
  • Electronics and Electrical Industries: Coiled Spring Pins hold significant importance within the electronics and electrical industries. They are essential for securing connectors, circuit boards, switches, and a range of electronic components. These pins ensure dependable electrical connections, protect against damage caused by excessive movement or shock, and withstand the thermal demands typically associated with electronic devices.
  • Defense and Military: Coiled Spring Pins are used in defense and military applications because of their exceptional reliability and durability. These pins are deployed in crucial systems such as military vehicles, weapons, and communications equipment. Their capability to withstand extreme conditions and ensure secure connections in demanding environments is vital for successful military operations.

Other industries that make use of Coiled Spring Pins include: the Medical Industry, where this pins are used to provide secure connections to surgical instruments, orthopedic implants, dental equipment, and diagnostic tools; the Consumer Goods Industry, where these fasteners are used in furniture, locks, hinges, power tools, toys, and other items that require secure and durable fastening; and the Machinery and Manufacturing Industries, where these pins provide secure fastening solutions for components such as gears, pulleys, shafts, and bearings.

What standards, materials and sizes are available?

Coiled Spring Pins are readily available off the shelf in Steel, with a Thermal Black finish, and in series 420 Stainless Steel.  Standard stock sizes for the head diameter are Inch from 1/16 to 3/8, and length from 1/4 to 3.

Commercial Standards include:

  • Inch: ASME B18.8.2, ASME B18.8.3M
  • Metric: ISO8748, ISO8750, ISO8751

Mil-Spec standards include:

  • MS39086, MS51923, MS51987, NAS1407, NAS561

Are there other factors to consider?

YES!! Installing Coiled Spring Pins requires a few essential tools to ensure proper placement and secure attachment. Below are a few tools that you might need in order to properly install them on a desired application.

  • Hammer/Mallet: To safely and accurately drive the Coiled Spring Pin into position, without causing distortion or deformation, it is necessary to use a hammer or a mallet, and to gently strike the coiled spring pin into position.
  • Pin Punch Tool: A pin punch tool could be used to drive the Coiled Spring Pin into a pre-drilled/tapped hole. This tool guarantees precise alignment and prevents any potential damage to the pin during the installation process.

Coiled Spring Pins at MF Supply

We currently offer:

  • A full range of commercial parts, including parts that are ROHS compliant.
  • Inch Coiled Spring Pins are now available for online purchase at our website!
  • Please send a Request for Quote for your Mil-Spec and Metric series needs.
  • Brand names and generic equivalents.
  • Custom made parts per print.

For more detailed information on Coiled Spring Pins or other products, visit us at our website or Request a Quote today, and our MF Supply team of sourcing experts can help you find what you need. Finding the right screw for you” is our tag line after all!

Book a one-on-one consultation with our President, Robin, to discuss how MF Supply can help you solve your Industrial Sourcing, Fastener, and Safety concerns.

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Six Reasons To Buy From MF Supply

  • Full eCommerce Enabled Website With Technical Manual Available 24/7 – Visit our website and Create a New Account, track online orders, browse our product catalog, check technical specs, subscribe to our blog, or buy online.  We are adding items and improving functionality daily!
  • Same Day Shipping From The USA – Our hardware products are in stock and ship to you directly from our USA based distribution centers. 
  • Functional Equivalents To Expensive Brand Names- We stock and source alternatives to brand name fasteners, reducing long lead times and saving you money.
  • Creatively Solve Problems – We are sourcing experts, offer competitive pricing and specialize in finding hard to find parts and reducing long deliveries.
  • One-Stop Shopping On Certified Hardware – We stock and source a full line of fasteners including Mil-Spec, DFARS compliant and other industrial products.
  • WBE/WOSB Woman Owned Certified Small Business – To meet your diversity & set-aside needs.

MF Supply is a WBE/WOSB certified supply chain partner to business, industry and government.  We are sourcing experts and stocking distributors of Hardware, Precision & Mil-Spec Fasteners and Safety supplies.  For more than 50 years, we have been supplying manufacturers in the electronics, industrial, commercial, aerospace and military markets with the full range of fastener products and services.  Our Cage Code is 58QG4 and our registered name is RL Supply Inc dba MF Supply.