R Pin

R Pin

R Pin


R-pins, also known as R-clips, R-keys, or hairpin cotter pins, are springy fasteners commonly used to secure the ends of round shafts such as axles and clevis pins. They are characterized by their unique shape resembling the letter "R" and are crafted from hardened metal wire for durability and flexibility.


R-pins are designed with a straight section that can be inserted through a hole in a shaft, followed by a curved section that clips around the outside of the shaft, holding it securely in place. This configuration allows for easy insertion and removal while ensuring reliable retention of shafts and components.

Types of R Pins

R-pins are available in two main types: single coil and double coil.

  • Single Coil: Primarily used for general applications.
  • Double Coil: Suited for more demanding uses and often equipped with retaining tethers to prevent loss when removed. Double coil types offer more even stress distribution for enhanced longevity.


R-pins find extensive applications across various industries:

Trucks, Trailers, and Utility Vehicles: Commonly used for hitch pin clips to prevent dislodgment of hitch pins, ensuring equipment security during transportation.

  • Automobile Manufacturing: Serve as hood pins to prevent hood panels from opening unexpectedly, especially in high-speed conditions.
  • Military and Defense: Brass R-pins can be utilized as button attachments for uniforms, providing a secure fastening solution.
  • Radio-Controlled Cars: Act as body fasteners to secure the body frame to the motor in RC cars, ensuring stability during operation.

Material and Standard Sizes

To ensure durability and flexibility, R-pins are typically crafted from springy materials such as zinc-coated steel, stainless steel, or special alloys like beryllium copper. These materials offer corrosion resistance and longevity, making them suitable for diverse environments and applications.


R-pins adhere to international standards such as DIN 11024, ensuring consistency and quality in manufacturing. DIN 11024 specifies dimensions for R-pins, including form D for double coil spring cotter pins and form E for single coil spring cotter pins.

R-pin Material

To fully function as securing devices, most R-pins are usually made from springy materials to facilitate durability and flexibility. It is also important for these clips to be long-lasting, so most are made from corrosion-resistant materials like zinc-coated steel and stainless steel. Depending on the environment and use, R-pins can also be made from special alloys like beryllium copper alloys. These can be aged and hardened to exhibit spring-like properties while also being highly conductive, high strength, and capable of operating in extreme temperatures.

R-pin Standard Sizes - DIN 11024

Standards are a key part of international trade as they ensure quality and safety in both products and services provided by manufacturers worldwide. These standards minimize defects, improve quality control, and make systems safer and more efficient. R-pins benefit from international standards with the DIN marking or the Deutsches Institut für Normung, a German national organization responsible for unifying products and processes, such as quality performance, characteristics, dimensions, etc. The DIN 11024 standard for R-pins ensures consistency and quality for product manufacturing. DIN 11024 form D stands for double coil spring cotter pin & DIN 11024 form E stands for single coil spring cotter pin. The figure and table below show the different dimensions available for DIN 11024 R pins.

DIN 11024 Form D - Double Coil Spring Cotter Pins Dimension:

d1 (mm)d2 (mm)d3 (mm)d4 (mm)l (mm)Weigh in kg/100 pcs


DIN 11024 Form E, Single Coile Spring Cotter Pins ( R clips ) Dimension:

r pin form e




R-pins are versatile fasteners known for their reliability, ease of use, and broad applicability across various industries. Whether securing heavy machinery or providing safety measures in automotive applications, R-pins play a vital role in ensuring the integrity and functionality of mechanical systems.

About Us

Welcome to Hariome Spring Industries, a premier destination for top-quality springs in India. Established in 1989, we have been at the forefront of spring manufacturing, offering a comprehensive range of heavy-duty springs, wire springs, strip springs, and wire forms to meet diverse industrial needs.

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At Hariome Spring Industries, we boast a wide manufacturing range, capable of producing wire springs ranging from 0.1mm to 40mm. Our extensive product lineup includes compression springs, tension springs, torsion springs, back rod springs, extension springs, taper springs, flexible springs, hook springs, bevel springs, conical springs, Belleville springs, R clips, C clips, metal stamping springs, spring washers, wire forms, and more. Additionally, we offer customized spring solutions tailored to our customers' specific requirements.

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