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Whether it’s your room’s door or the cargo door of an airplane, pins are essential for secure connection between parts!
In this guide, we’ll introduce you to 27 types of pins with unique features and uses. This covers DIY to industrial-level applications. So, let’s jump into the topic to pick the right pin type for your project.
What Are Pins?
Pins are used to connect or fasten objects together permanently or temporarily. These are essential elements for secure structure and stable connection in machinery, engineering parts, and other instruments.
You need pre-drilled holes where the pins are inserted and tightened. This way, the joining of parts becomes robust.
Therefore, pins are widely used in mold, electrical equipment, and the manufacturing process. These are made of different types of materials and are also available in varying shapes and sizes.
Types Of Pins Based On Function
1. Cotter Pins
Cotter pins are made by bending metal to form a securing structure. These are widely used in construction, automotive, agriculture, and other industrial fields. The standard cotter pin has a teardrop-shaped head with two unequal legs, which you can easily separate. These are popularly known as split cotter pins.
However, besides this standard variant, cotter pins can be of different other types. These are as follows:
a. Circle Cotter Pin
Circle cotter pins have a circular closed-loop design. These are used where sharp ends are not preferred, e.g., fabric securing.
b. Hammerlock Cotter Pin
As the name suggested, one end of these pins is designed to be hammered. They are also known as extended cotter pins. Compared to standard cotter pins, they are longer and more robust.
c. Ring Cotter Pin
Ring cotter pins are also known as rue rings. They are a hybrid between a circle cotter pin and a twist pin. You can use them to secure rods and spindles.
d. T-Head Cotter Pins
The T-shaped head of these pins offers a secure pulling from the pin. These are usually made of carbon steel and are widely used in automotive and aerospace.
e. Hairpin Cotter Pin
They are also known as external hairpin clips, hitch pin clips or R-clips. They have a spring-like design, which you can use multiple times without significant damage.
2. Lynch Pins
Lynch pins are popular for securing wheels, axles, shafts, etc. They have a ring-like structure with a pin inside. When you insert the ring into a hole, it automatically locks the pin by snapping over the end. Compared to cotter pins, they are stronger and suitable for heavy-duty industrial applications.
3. Spring Pins
Spring pins are cylindrical in shape and have a slit throughout its length. They are hollow inside and have a diameter greater than the holes to fit in. As they create a spring-like tension to fasten parts, spring pins are also known as tension pins. They are of two types:
a. Coiled Spring Pin
Coiled spring pins are made by rolling a metal sheet into a spiral. They have high load-bearing capacity and are suitable for heavy-duty applications.
b. Roll/slotted Spring Pin
Roll spring pins have longitudinal slots. This allows you to compress the pin during installation offering a tight connection.
4. Snap or Wire Lock Pins
Snap or wire lock pins are also known as snapper pins. The head of the pin is connected to the other end with a wire-like structure. They can be single-wire or double-wire snap pins. This brings a spring mechanism locking system and prevents the pin’s movement out of its hole.
5. Hitch Pins
Hitch pins have a swivel handle at one end and a groove on the other. These pins are placed into the drilled holes and locked with a cotter pin, which is inserted into the groove. Hitch pins are widely used in the agriculture industry to connect the tractor to different machinery.
6. Safety Pins
Safety pins are the most common variant of pins that’s familiar to everyone. It has a sharp pointed end secured by a spring-loaded clasp. These are used for fabric fastening. No pre dried holes are required in this case. The sharp end of the pin makes tiny holes in the fabric and locks it within the clasp.
7. Clevis Pins
Clevis pins have a hole at one end and a flat non-treated head on the other. Similar to hitch pins, these pins are inserted into the pre-drilled holes and secured with clevises or cotter pins. They can come with multiple holes at the end to provide an adjustment facility.
8. Bent Pins
Bent pins are an affordable alternative to hitch pins. They have a 25° bend head at one end and a hole on the other, which is secured by a cotter pin or bridge pin. Bent pins are made of stainless steel, carbon steel or alloy steel and used in the furniture and construction industry.
9. Toggle Pins
Unlike hitch pins, toggle pins don’t need a cotter pin for fastening. They have a smooth shaft with a spring-loaded toggle on the end. This prevents the pin from sliding out.
10. Drive Pins
Drive pins are cylindrical shaped pins with pointed/flat ends that are driven into the surface, usually by hammering. These are widely used in construction and wooden works.
11. Weld Pins
Weld pins are designed to connect metal parts by welding. They have a slender shaft with a head that fuses to the metal sheets. Weld pins are robust in structure and have standard resistance against welding equipment. You will find their use in industrial applications, e.g., construction, HVAC systems, etc.
12. Groove Pins
Groove pins are cylindrical in shape with longitudinal grooves. These groves can be in different configurations, including spiral design. These pins are inserted in the holes between two parts to provide additional torsional protection for accurate positioning.
13. Bullet-Nose Pin
Bullet-nose pins are used to align and position the components correctly. They have a round or diamond-shaped tip that looks like a bullet. These pins are complemented with a liner or a mating bushing to ensure a secure fit.
14. Dowel Pins
Dowel pins are a better alternative to screwing or bolting in applications where quick installation or part removal is essential. These are cylinder-shaped straight pins. Unlike drive pins, you need not hammer them; doing so will damage the pin. Instead, press the dowel pins into the holes to align or position parts.
However, dowel pins are of different types based on size and design; these are as follows:
a. Oversize Dowel Pin
These dowel pins are bigger than the regular size. You can use them for worn and enlarged holes.
b. Undersize Dowel Pin
These pins are smaller than standard dowel pins.
c. Pull Dowel Pin
Pull dowel pins feature a hole in one end. You can insert screw in the hole and easily remove the pin.
d. Stepped Dowel Pin
Stepped dowel pins have a diameter difference between the top and bottom ends. Besides, some may have holes in the ends for easy pin removal.
e. Parallel Pin
These dowel pins have two different tolerance levels for the ends.
f. Knurled Pin
A part or the entire surface of these dowel pins is knurled. Such a design offers a better grip than straight dowel pins.
15. Drift Pin
Drift pins are widely used in woodworking, metalworking, machinery, and construction projects. These are tapered pins with pointed ends (one or both ends). They are used to reposition or align the holes before bolting the parts together.
16. Spring Plungers
Spring plungers are mostly used as positions, indexing, and alignment pins. They have a pulled and hand-retractable mechanism and usually have a lock patch for vibration resistance. You can use these pins in tight and congested spaces with ease.
17. Locating Pins
Locating pins are designed to be in the correct position of the parts. They ensure perfect fittings of all components and strengthen the final product. Different types of locating pins are available; these are as follows:
a. Diamond Locating Pin
These pins have a diamond-like head with four flats and offer greater resistance to rotation.
b. Round Locating Pin
These are cylindrical-shaped pins used in general alignment tasks. You need accurate hole spacing as they are highly sensitive to misalignment.
c. Cone Locator Pin
They have a cone-shaped tip and are used with a liner or mating bushing.
d. Floating Locating Pin
The floating locating pins have a head similar to round locating pins. However, they can move slightly on one axis, keeping their position fixed on the other.
18. Detent Pins
Detent pins are dowel pins with a ring on one side and a detent on the other. They do not need cotter pins to lock. So installing and removing these pins is super easy. They are also known as quick-release pins for this feature.
19. Positive Lock Pins
Positive lock pins have an upgraded design compared to detent pins. They come with a locking mechanism with a button on the head. Pressing the button, you can unlock the pin.
20. Retractable Spring Latch Pins
As the name suggests, the tips of these pins are retractable with the spring mechanism. This allows for the extension of the pin’s position for easy installation and removal. They come with a latch that holds the pin in place.
Besides, retractable spring latch pins are made of stainless steel plated with zinc for anti-corrosive properties. So you can use them for heavy-stress applications.
21. L-Handle Pins
L-handle pins come with a ball-locking mechanism. All you need to do is place the pin into the hole and twist the handle to lock it. You can use them to attach accessories or components to equipment parts.
22. Taper Pins
Taper pins are cylindrical pins with a gradual decrease in diameter. This allows proper fit within the hole for a robust connection. These are of two types:
a. Threaded Taper Pins
The end with a smaller diameter of these taper pins has a threaded section. This allows easy removal of the pins.
b. Non-Threaded Taper Pins
These are solid taper pins that gradually reduce their diameter to 1/4″ per foot from the larger to the smaller end.
24. Clamping Pin
Clamping puns have a cylindrical body with a climbing bolt that allows tightening or loosening of the pin. However, some clamping pins come with a knurled knob for easy installation. They are used along with bushing or adjusted with a collar.
25. Pivot/Hinge Pin
Hinge pins are a very popular variant of pins used in door hinges, gate hinges, and other applications. They allow pivoting or rotation of two connected parts within a fixed axis, as you can see on door joints.
26. Escutcheon Pin
Escutcheon pins are basic bins with a pointed end at one side and a semi-spherical or flat head at the other. The pointed part is inserted into the working surface by hammering the other end. You can use these pins for light-fastening jobs like hanging photo frames or nameplates.
27. Expanding Diameter Pin
Expanding diameter pins have a unique design that allows you to extend their diameter once they get into the hole. They fill up the entire space of the hole, ensuring zero clearance. Thus, they create a tight and secure connection. These are suitable for use in engine mounts and helicopter blades.
Types Of Pins Based On Material
Brass Pins
The aesthetic and antic appearance of brass metal makes these pins suitable for decorative application. Besides, they are rust-proof and have good machinability and thermal conductivity.
Aluminum Alloy Pins
They are lightweight and corrosion-resistant. These features make aluminum alloy pins ideal for aerospace and automotive uses.
Carbon Steel Pins
Carbon steel pins are used in general mechanical applications. They are durable, strong, and rust-free.
Stainless Steel Pins
Stainless steel pins are known for their robustness and durability. They are rust-proof and suitable for use in an environment dealing with high temperature, moisture, or chemicals.
Alloy Steel Pins
Alloy steel pins are made by combining steel with other metals like chromium, nickel, or molybdenum. This increases the strength of the metal and makes it suitable for heavy-duty applications.
Copper Pins
Copper pins are widely used in electrical applications due to their highly conductive nature. However, copper pins are softer than other metal pins.
Titanium Alloy Pins
Titanium alloy pins are lightweight, durable, and have high strength. You can use them in aerospace, marine, and biomedical fields.
How Pins are Made?
Method 1: CNC Machining
CNC machining is best for small pins requiring accurate design. Metal blocks are placed under the machine, which gives the pin the desired shape by chopping the metal block. You can use different types of metal, like steel, brass, or aluminum, to make pins via CNC machining.
However, the duration of the entire process depends on the complicity of the pin design. And once the pin gets out of the CNC machine they are sent for finishing and quality check.
Method 2: Stamping
In the stamping process, metal sheets are pressed over pre-designed dies made for specific pins. As the metal sheet gets into the designed die, it takes the shape of the pin. This method is suitable for large pins and fast production requirements.
Method 3: Forging
The forging can be hot or cold. In the hot forging process, metals like steel or titanium are heated and pushed onto a forging press. This process is suitable for large points with complex designs.
In the cold forging method, metals are shaped at room temperature by applying high pressure. This process is more applicable for small and high-strength pins.
How To Choose The Right Pin Type?
Consider Application
The design of pins is specific to the application. Therefore, you must consider the application to pick the right pin.
| Industries | Application Of Pins |
| Automotive Industry | Cotter pins are used in automotive wheels. Besides, the car’s shock brakes use clevis pins. |
| Medical Industry | Anti-corrosive pins are widely used in the medical industry. For instance, cotter pins are used in breathing systems, and dowel pins are installed in surgical retractor holders. |
| Machines and Equipment | The parts of the machines are connected using different types of pins. For example- clevis pins are used in textile machinery due to their high vibration tolerance. Snap pins, spring plungers, weld pins, and detent pins are also used in machinery and equipment. |
| Aerospace | Aluminum alloy and titanium alloy pins are suitable for aerospace due to their lightweight features. For instance, different types of locking pins are used in cargo doors and landing gears. |
| Robotics | Robotics requires small and precious pins for joining parts. Pins made out of the CNC machining process are used in such applications. |
Material Of The Pin
You must consider the environment, load, and application to choose the right pin material. For example, in outdoor or coastal areas, you need high corrosion-resistant pins. In this case, stainless steel and titanium alloy are best.
Again, for weight-sensitive applications, you must pick lightweight pins. For example, titanium alloy pins are super lightweight and ideal for aerospace usage.
Tolerance
The tolerance level refers to the variation in the dimension of the pin. You should follow international standards to consider the maximum tolerance level of the pin.
Size and Shape
Pins are available in different shapes and sizes. Larger pins are used in industrial applications, whereas smaller pins are used in joining or securing precise machinery. The diameter of the pin is essential here. This is because, if the pin is smaller than the hole, it will loosen up, and the connection will no longer remain strong.
Capacity
The load capacity of the pin varies for different types. For appropriate bending and proper inserting, you must consider its capacity. For instance, the loading capacity of a clevis pin is up to 8,000 pounds.
Likewise, you must check the capacity of the pin you use to ensure it can take the weight. However, remember the pins’ capacity requirement varies for different applications.
Wrapping Up
Before picking any pin type, consider its uses, environment, and load capacity. This will help you pick the ideal type.
However, if you are looking for pin manufacturers for your business, check Richconn services. We specialize in CNC machining, offering you precise pins to fit your requirements. Contact ASAP!
FAQs
What are the advantages of using pins?
Pin fasteners are durable and tightly secure two components. Besides, they ensure proper alignment of the parts for enhanced stability of the final product.
How do you determine the size of the pins?
To determine the size of the pin, consider its thickness and diameter to ensure it fits perfectly within the hole.
Which are corrosion-resistant pins?
Titanium, stainless steel, or galvanized steel pins are corrosion-resistant. You can use them in an environment with high temperature, chemical, and moisture content.
Are custom-made pins available for specific applications?
Yes, different manufacturing companies provide custom-made pins to meet specific application requirements. They consider the use of the pin and make customizations based on shape, size, thickness, and design.
Which material is best for pins?
The best material for a pin depends on its application. For example, brass pins are used for decorative items. Again, in heavy-duty installation, steel alloy pins work great.
