Pin Fasteners-How Do Pin Fasteners Work? | Reid Supply
Mechanical fasteners, such as screws, bolts, nuts, and rivets, are essential components in engineering and machine design, and other modern industry applications. The need for these types of fasteners has grown in tandem with the advancement of industrial technology, resulting in a wide selection of specialty fasteners available on the current market.
In today’s article, we’ll discuss unthreaded fasteners, better known as pin fasteners. We’ll talk about what they are, how they work, and what types of pin fasteners there are.
What Are Pin Fasteners?
Pin fasteners are cylindrical pins used to keep industrial equipment and machine components snugly and securely together or in a proper alignment. They come in various forms and sizes, and are typically made of metals, like stainless steel, copper, and brass, though hard plastic applications also exist.
However, it’s worth noting that unlike screws and threaded bolts and studs, these specialty fasteners are unthreaded mechanical fasteners designed to be inserted in pre-formed through holes. As a result, they usually require less tools to operate, and allow for quicker installation and removal.
How Do Pin Fasteners Work?
Pins work by preventing the industrial machinery or other coupling elements in which they are inserted from decoupling from the fastening system. This is done in several different ways, depending on the type of fastener used in your application.
Are Pin Fasteners Permanent?
Pin fasteners are assorted into two basic types of pins: semi-permanent pins and quick-release pins.
· Semi-permanent pins — These are used in applications which don’t require their frequent removal. As such, the installation of semi-permanent pins usually requires the application of pressure, or the aid of different tools.
· Quick-release pins — These pins are locked in place by a special spring-loaded mechanism, allowing them to be easily and quickly installed or removed. As such, they don’t usually require installation tools.
Types of Pin Fasteners
Machine fastening pins come in varying configurations, and are commonly found in numerous applications.
Clevis Pins
Clevis pins have a hinge-like form; a cylindrical shape with a head on one end, and one or more holes running through the diameter. These are perfect for applications that require a movable connection between two linked components, but due to their shape and function, they’re used in conjunction with cotter pins.
They’re particularly useful in situations in which the shank must rotate, such as securing a turnbuckle. Clevis pins can be paired with a shackle, for a more secure connection.
Cotter Pins
Cotter pins, also known as split pins, are commonly used as safety pins to hold other fasteners in place, especially in high-stress applications, where other fasteners might be subjected to significant stress and vibration. They’re available in 18 different sizes, and make an excellent choice for securing slotted bolts and screws, thanks to their design.
Metal Dowel Pins
Dowel pins, also known as straight pins, are typically cylindrical semi-permanent pins mainly used to lock machine parts in a fixed position, or to maintain proper alignment. This is the most basic pin type which derives its power purely from frictional forces. In addition, they can be ribbed or hexagonally shaped to provide additional spin resistance in atypical applications.
Grooved Pins
Grooved pins are solid steel pins with three or four grooves swaged along their length. This allows grooved pins to offer more elasticity than a solid dowel pin, at a very minute cost in terms of shear resistance. However, they’re significantly more durable than the elastic spring pins.
Quick-release Pins
Quick release pins, or Pip-pins, allow for a quicker location, alignment and fastening two components. These pins usually feature two spring-loaded balls at the base of the pin, which lock it in place, preventing the pin’s removal. The pin can only be removed by actuating the release mechanism, which releases the balls at the base of the pin, allowing the user to freely remove the pin from the hole.
Self-Clinching Pins
Self-clinching pins deliver a sturdy flush-head assembly in materials that are as thin as 1mm (or .04 inches). They’re fantastic in applications that require high push-out performance and prioritize high push-out strength. It’s worth noting that the pin itself can be threaded internally or externally.
Spring Pins
Spring pins, also known as slotted pins are formed from sheet metal rolled into a partial cylinder, with a slot across its length, and chamfered edges. These are the most universal, economical, and time-saving fasteners on today’s market. Spring pins replace a wide variety of different fasteners in more general applications.
They’re quite affordable, as they’re usually made in one piece, and cut-down to the preferred or required size, but there are pre-cut lengths available on the market. They have a larger diameter than the hole in which they’re installed, allowing them to compress along their length as they’re pushed into the hole.
This creates tension that secures the pin in place. The installation is quite forward, and usually requires only a few gentle taps with a hammer, provided that the hole is pre-fabricated. The removal usually requires a pin puncher tool, and a hammer.
Tapered Pins
Taper pins are derivatives of dowel pins, with one notable distinction; a slight taper along their length. There are semi-permanent pins typically used on components that require frequent assembly and disassembly.
What Tools Are Needed for Pin Fasteners?
Depending on the application, installing and removing pin fasteners usually requires tools.
Hand Tools Needed for Pin Fasteners
Depending on the type of pins you’re installing, you might need a small hammer, nose pliers, a flat head and a Phillips screwdriver.
Power Tools Needed for Pin Fasteners
Many fastener types, including rivets, require prefabricated holes for installation. Depending on your assembly, you may use a hand-held drill, an electric drill, a drill press, or even a milling machine. Hole size selection largely depends on the diameter and type of pin fastener you’re installing.
Summary
Pin fasteners have been a commonplace in mechanical engineering for decades to secure the position of two or more equipment or machine parts, relative to each other. If you’re in the market for different pin fasteners, Reid Supply — a premier provider of industrial components — offers a wide assortment of different types of threaded and unthreaded fasteners.