What is a spring split pin?

What is a spring split pin?

Split spring pin, also known as cylindrical pin, is a headless hollow cylindrical body, axially slotted, and chamfered at both ends. It is used for positioning, connection and fixing between parts; it needs to have good elasticity and resistance to Shear force, the outer diameter of these pins is slightly larger than the mounting hole diameter.

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We have a patent certificate for springs, and have the ability to develop products together with customers. Some products can provide free samples to customers.


We have 30 years of manufacturing and R&D experience. It has passed the IATF 16969 automotive quality management system, and has more than 200 sets of professional spring equipment, which can guarantee the quality.

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Wenzhou Heli Spring Manufacturing Co., Ltd. was founded in 1992. It is a high-quality spring manufacturing enterprise integrating design, production, sales and service. The current products include: compression springs, torsion springs, extension springs, auto parts springs, wire forming springs and spring sheets, etc.

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What are the installation methods of spring cotter pins?

There are usually two installation methods for spring cotter pins, one is manual installation and the other is mechanical installation. For manual installation, insert the spring cotter pin into the hole that connects the object, and then press the opening part with your finger so that it can be inserted and locked. For mechanical installation, using a professional installation tool, a spring cotter pin is inserted into the hole that connects the object, and then it is compressed and locked with a tool.

What are the requirements for the size and material of spring cotter pins?

The size and material of the spring cotter pin should be selected according to the specific application scenario and requirements. Generally, the size of the spring cotter pin should be determined according to the size and weight of the connecting object, and the material should be selected steel or stainless steel material with good elasticity and corrosion resistance.

What does a spring pin do?

A spring pin (also called tension pin or roll pin) is a mechanical fastener that secures the position of two or more parts of a machine relative to each other. Spring pins have a body diameter which is larger than the hole diameter, and a chamfer on either one or both ends to facilitate starting the pin into the hole.

When using split pins, you should pay attention to five key points

1. Eye circles should be made as round as possible.
2. The cross section of the two feet of the cotter pin should be circular, but it is allowed to have a fillet with a radius of r=(0.05~0.01)dmax (d—the diameter of the cotter pin) at the intersection of the plane of the two feet of the cotter pin and the circumference.
3. The gap between the two pins of the cotter pin and the displacement of the two feet should not be greater than the difference between the nominal size of the cotter pin and dmax.
4. If the split pin is allowed to be made into an opening, the angle α between the inner planes of the two feet should meet the specifications.
5. The surface of the split pin is not allowed to have burrs, irregular and harmful defects.

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Frequently Asked Question

Do you have any question?

Cotter pins are wire formed pins with two prongs that separate during installation. They are used as a locking device to hold pins or castle nuts in place. These low-cost and highly versatile fasteners are used virtually everywhere.

A head on one end acts as a stop, while a hole punched through the opposite end can be fitted with a cotter pin or simply tied off or moused to keep the clevis pin in place. A spring pin is formed with a groove or slot, allowing the pin to fit into holes of a smaller diameter than the pin itself.

Also known as a split pin, a cotter pin is a simple fastener that's used to secure a bolt — or any other rod-shaped fastener — in place. As shown in the adjacent image, cotter pins consist of a narrow U-shaped piece of metal with a flared and circular top.

A spring cotter pin is a mechanical part, also known as a spring pin, elastic pin, spring snap ring, which is often used to connect two parts or fix parts. It is usually made of spring steel with open or round rings and is elastic. Such a part can be joined by inserting it into a shaft hole or hole and then rotating it 90 degrees to lock it in place. Due to its elasticity, it can withstand axial and radial loads to a certain extent, making the connection more robust. Spring cotter pins are widely used in various mechanical equipment, such as automobiles, bicycles, furniture, etc.

Machinery manufacturing industry: spring cotter pins are often used in various equipment and machinery in the machinery manufacturing industry, such as construction machinery, textile machinery, packaging machinery, etc. Automobile manufacturing: Spring cotter pins are widely used in various vehicles and parts in the automobile manufacturing industry, such as car seats, doors, windows, engines, etc. Furniture manufacturing: Spring cotter pins can be used for various furniture in the furniture manufacturing industry, such as chairs, tables, cabinets, etc. Electronic manufacturing: Spring cotter pins can also be used in various equipment and parts in the electronics manufacturing industry, such as computers, mobile phones, cameras, etc.

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