Spring pins are also known as roll pins and are designed to be inserted into a hole that is smaller in diameter than the pin itself. When the pin is being installed, it is sprung to decrease its diameter, which allows for a firm fit while exerting a retaining strength against the walls of the hole. They are usually made from materials like carbon steel, alloy steel, and stainless steel with spring-like elastic characteristics. Spring pins can also be used as positioning points, locking devices, shafts, anti-chafing surfaces, or as sleeves for wiring. There are mainly two types of spring pins that are coiled and slotted.
How Does Spring Pins Work?
Spring pins are first inserted into a hole with a smaller diameter than the spring pins themselves. After it is inserted, they decrease in diameter upon installation, which allows a retaining force against the walls of the hole. When the spring pins are compressed into the hole, they apply pressure to its sides as it starts expanding to its original diameter. This force creates some friction which holds the pin securely inside the hole.
Spring pins are generally made from a thin sheet of material wrapped or curved around to form the outer diameter of the pin. They are made from steel sheets and consist of a chamfer at each end, allowing the pins to be smoothly inserted into the holes.
The components may hold a component on the shaft by entering the pin through the shaft in a perpendicular direction to its axis. These spring pins may also be used to insert them through the concentric holes in two or more two components.
Types of Spring Pins
There are two main types of spring pins classified:
Slotted Pins
In slotted pins, the sheet material is curved around at 360 degrees, leaving space for the cap to be compressed. These pins are more commonly used in applications where rigidity is needed or for light-duty applications.
Spiral Pins
Compared to a slotted pin, the spiral pins are produced from lighter gauges of the thin sheet material, but it is curved around more than to complete revolutions. This creates a strong pin that can maintain its flexibility. This is effective for decreasing stress concentrations and fatigue failures. Spiral pins are commonly required in more heavy-duty applications with cyclic loading.
Applications of Spring Pins
Spring or roll pins are simple fasteners that are highly cost-effective industrial fasteners that need very little preparation. However, a few times, the operator may need to drill a hole before installation. Both the coiled and slotted spring pins can be used for various applications. For example, you can often use electrical spring pins as electrical connectors. These fasteners are also appropriate for stamping, casting, and other production-related operations. However, the slotted spring pins are more capable of withstanding more excellent shocks and vibration effects than other such products. The spring-loaded pins may consist of a quick-release mechanism appropriate for applications with limited space. Bulk pricing is often available for all types of spring pins by which you can save some money.
Specifications
Spring pins are available in metric and English sizes and have specifications that are:
- Size
- Length
- Material of construction
English pins are measured in inches or fractions of an inch. In contrast, the metric fasteners are measured in millimeters or centimeters. The size of spring pins is expressed in a standard diameter.
