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Cotter Pins: What Are Cotter Pins?

How Do Cotter Pins Work?cotter pins

A cotter pin acts as a locking mechanism and can be used in many different situations. Cotter Pins are a simple to use fastener that requires nothing more than a bolt with a hole in it (and a drill if the bolt does not have a hole), a pair of pliers and a castle nut.

 

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How To Install A Cotter Pin

Installing a locking pin is a simple process:

  1. Attach the castle nut to the bolt and fasten it into place.
  2. Make a mark on the bolt or leave the castle pin installed.
  3. Using a drill and bit, drill a hole into the bolt at this point straight through the cross-section of the bolt. You can make a starting point by using a metal punch.
  4. Remove any metal filings from the hole and insert the cotter pin.
  5. Using pliers, bend the ends of the cotter pin away from each other so the cotter pin cannot come out of the hole.

Pro Tip: When bending the cotter pin, try to round the points to look back in at the fastener. This will prevent them from catching on anything accidentally.

To Watch The Installation Of A Cotter Pin Check Out The Video Below:

Are Cotter Pins Necessary?

Cotter pins, while not considered necessary to every installation, may be necessary depending on the application. For example: A motorcycle front wheel is often held on by a castle nut and a cotter pin as it is subject to intense constant vibrations.

How Are Cotter Pins Measured?

Cotter pins have two measurements that matter for an installation. To choose the correct cotter pin you need to know the diameter and the length of the pin.

To determine the length of the cotter pin measure from the base of the rounded portion (“the eye”) to the end of the shorter side.

To determine the diameter of the cotter pin measure both pins together. The rounded portion is not supposed to fit through the hole so the hole should not be bigger than the eye.

cotter pin measurement diagram

Are Cotter Pins Reusable?

Cotter pins can be made from several different materials that are soft enough to bend. Typically, when deforming the pin once, the pins keep their strength and provide a strong locking mechanism that can be relied on.

As a general rule, cotter pins should not be reused as the extra bending weakens the pin. This can lead to the pin failing where a fresh pin would not resulting in a broken lock allowing the nut to spin loose.

How To Remove A Cotter Pin

Removing a cotter pin is an extremely simple task. Simply use pliers to bend the arms of the pin back straight enough to squeeze through the hole. If the pin is worn, these arms may simply snap off and then the rounded eye portion can simply be pulled out and replaced with a new one.

Why Should You Use A Cotter Pin

Cotter pins are used in many different installations. They can act as a quick locking mechanism that is easy to remove and replace but their main benefit is that they will prevent a nut from coming loose due to vibrations of any kind.

While many varieties of lock nut exist that are quick to install, they all come loose over some amount of time depending on how strong the vibrations are. A cotter pin completely removes the chance of a nut loosening unless the force acting on the nut is strong enough to shear through the pin.

What are Cotter Pins Used for?

Cotter pin is a fastener used for locking the nuts onto the bolts. You have to drill a small hole into the bolt to use it. Cotter pins are commonly used in Clevis pins, as it has a premade hole in it.

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Difference Between Cotter Pins and Split Pins

Cotter pins are made of mild steel and are used for locking nuts at the place. They are inserted into the hole of the bolt and are then bent into different shapes to prevent the nut from falling out. Whereas Split pins are made up of harder grade steel. It is once inserted into the hole to lock the nut.

Types of Cotter Pins

Below are some of the most widely used cotter pins;

  • Hair Pin Cotter Pins

These pins are easy to install and remove, They are commonly used in clevis pins to secure its end.

  • Wire Snap Cotter Pins

These pins are used in clevis pins or are used in shafts to keep the components aligned in one place.

  • Hammer Set Cotter Pins

These pins are tapped with a hammer (after inserting) for a temporary hold.

  • Wedge Lock Cotter Pins

After inserting these pins, hammer them to wedge the prongs open, this will ensure the stronghold.

 

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Fasteners In Salt Water Environments: What You Need To Know

Fasteners In Salt Water Environments

One of the biggest complaints we hear about are fasteners rusting prematurely. The first question we are likely to ask is “Are you within 20 miles of a salt water environment?”

Surprisingly, an overwhelming amount of customers say yes. It is commonly understood that metal rusts and that it rusts worse in corrosive environments. It is not commonly understood that those environments spread beyond what the eye can see, however, this should be one of the bigger factors taken into consideration when buying fasteners.

Stainless steel is a prime example of this. Almost anyone you talk to can tell you stainless steel is corrosion resistant, but did you know that grade 410 stainless steel is less corrosion resistant because it is heat-treated to be harder? or that grade 304 stainless is not suited for highly corrosive environments?

In fasteners, the material and sometimes even the grade matter when it comes to choosing the right fastener for your installations. There are several materials that do extremely well in salt-water environments, some that kind of work and some that are almost guaranteed to fail.

 

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What You Should Use

fasteners for salt water: aluminum, silicon bronze, 316 stainless steel

There are generally a few materials that work extremely well in salt-water environments. Depending on your needs you should aim to choose from the following:

  • Grade 316 Stainless Steel
  • Aluminum
  • Silicon Bronze

These materials (or specific grades) are ideal for salt-water environments because they can resist the corrosive effects that salt-water very well.

Another option to try is HDG (Hot Dip Galvanized) fasteners. HDG is a form of zinc coating that will protect the fastener from harm and is usually a cheaper option but is not a perfect solution.

HDG fasteners can handle well in certain salt-water environments but results can vary depending on if they are submerged, water temperature and air temperature. Due to these factors, we do not recommend it as it will likely not perform as well as the materials listed above.



Pro Tip

Although 316 stainless steel and aluminum are both listed as good materials to use in corrosion resistant environments, you also do not want to mix the two. If you do, the process of galvanic corrosion is more than likely to occur, resulting in a significantly shortened lifespan for your fasteners.

To see the fasteners we carry in these selections check out our marine grade and aluminum fasteners pages.

How To Install Set Screws

 

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How To Install Set Screwspre-installed set screw and allen key

Socket Set Screws are one of the more common screw varieties of fasteners that are commonly found in machinery. They are an excellent fastener choice for installations that have many moving parts due to their lack of a head. This means they can easily be installed and create a flush or countersunk finish. When space is critical and when parts need to slide near or against each other a set screw is the fastener of choice but they are a mystery to many people. So how do you install set screws?

Preparing The Hole

To begin, set screws are mostly installed into metal applications although they can be installed into anything as long as threading is present. To install a set screw from scratch, first a hole must be drilled into the material. We used a tap used to cut or restore threadingstainless steel block we had lying around for our example. We used a drill bit and some drill bit lubricant to ensure our bit did not overheat and dull while drilling.

After drilling the hole, we used a tap to create threading in the pre-drilled hole. Taps are used to cut or restore threading inside of a hole by using sharp cutting blades. While spinning the tap into the hole the flutes allow debris to fall and prevent the tap from overheating.

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Installing The Socket Set Screw

Socket set screws come in many different materials and point styles that can change the installation slightly. Some of these point styles include the following:

  • Cup – Standard basically flat point with no real visual qualities.
  • Cone – The tip of a cone comes to a full point and will press against the bottom of the hole when installed.
  • Half Dog – This point has a smaller protruding un-threaded portion making it easier to sit the screw into the hole.
  • Knurled Cup – This point has a knurled flat tip which digs into the material to help prevent accidental loosening due to vibrations.

The first step when installing a socket set screw into a tapped hole is to start threading it. With bigger sizes this can simply be done with your hands. Take the set screw and begin spinning it into the hole until the threading grips and begins pulling the screw into the hole. Then take the appropriately sized Allen wrench and insert it into the drive recess. Now all that is left to do is screw in the set screw until the set screw becomes flush or goes below the installation surface.

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Pro Tip

When drilling a hole for a set screw it is important not to over-drill the hole otherwise you may install the screw too far inside the installation material. Before you begin drilling the hole, measure the set screw against the tip of the drill bit and wrap blue tape around the drill where the screw ends.

This will prevent over-drilling and ensure you have the right depth for the hole. Also make sure to clear out and debris with compressed air prior to installing the set screw.

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Can You Install A Lag Screw Into Concrete?

 

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Can You Install A Lag Screw Into Concrete?

The short answer is Yes! You can install a Lag Screw into concrete. Installing a lag screw into concrete is not a difficult process but it does require an anchor to install properly.

Lag Screw and Lag Shield

Lag shields are concrete anchors that expand near the bottom to hold the shield inside of a drilled hole. They are made specifically for the installation of lag screws into masonry materials.

To install a lag shield into concrete first drill a hole that is the same diameter as the outside diameter of the lag shield. Before drilling you will also want to measure the length of the lag shield and drill down the length plus a little extra space .

Next take a hammer and tap the lag shield down into the hole you’ve drilled until its flush with the surface. Since the hole is the same size as the outer diameter, this should create a snug fit for the anchor.

Installing A Lag Screw Into Wood

Next make sure you have a lag screw long enough for the installation. For example, if you wanted to install a 2 x 4 to the lag shield, you would need to make sure the lag screw had 1-1/2″ of clearance and then about another 1″ to 1-1/2″ to install into the shield. This means you would need roughly a 3″ lag screw to complete this installation.

Once you have the proper lag screw, begin fastening the lag screw into the installed shield. This will push the lag shield apart in the hole creating a strong hold to keep your installation in place.

Types Of Masonry Anchors

 

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Types Of Masonry Anchors

There are many types of masonry anchors available today. The problem for many is determining which of these anchors they need to perform the job. Listed below are some of the more common fasteners found in the masonry field.

Drop In AnchorsDrop In Anchors With Setting Tool

A Masonry Drop In Anchor is mostly used in poured concrete.  They are used in high strength applications by fastening a bolt into the internal threading of the anchor. They are also available in coil threading (a coarser thread for coil threaded rod). Some masonry anchors have a lip to prevent the anchor from dropping too far into the concrete.

To install the drop in anchor, drill a hole the same diameter as the anchor and only as deep as the anchor itself. Then drop the anchor into the hole and seat the setting tool inside of it. Then hit the setting tool with a hammer. The bottom portion of the anchor will deform resulting in a wedged anchor that cannot be removed.

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Lag Shield AnchorsLag Shield Wedge Anchors

A Lag Shield Concrete Anchor is used in combination with a lag screw to create an anchor in concrete. Lag shields are made of two parts and when the lag screw is driven into the shield, it expands resulting in a tight wedge in the concrete.

Lag Shield Anchors are very similar to a drop in anchor but are designed specifically to take a lag screw. Lag screw anchors also do not require a setting tool to install.

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Masonry Concrete Screws

Masonry Concrete Screws, sometimes referred to as Tapcons, are probably the Tapcon Masonry Concrete Screwsmost common concrete fastener used. Concrete screws are easy to identify based on their bright blue coating. They are used for fastening wood or metal to different masonry materials. They are available in both Phillips flat head (for flush finishes) and hex head (for ease of installation).

Installing a concrete screw is very simple. First, drill a hole through both materials and then simply drive the screw into the hole. Make sure you use a screw that is long enough to reach through both materials otherwise you will not have a firm hold.

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Sammys Hanging AnchorsSammys Screws

Sammys Screws are a common anchor used for hanging applications. Most often installed vertically or horizontally, these anchors have a threaded opening used to receive threaded rod. Sammys are commonly used in HVAC applications for hanging duct. The term Sammys, much like Tapcon, is a brand name. There are many types of these hanging anchors available.

To install a Sammys screw, first drill a hole into the material and use a wrench or socket to drive the anchor into the material. Once installed to the silver head, remove the wrench and screw in a piece of threaded rod.

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Hammer Driven Pin AnchorHammer Drive Pin Anchor

A Hammer Driven Pin Anchor is a small anchor which is mostly used to fasten plywood to concrete. These anchors are very simple to use. They have a lip over the head making it compatible with holes that may have accidentally been driven too far into the material.

To install one of these pin anchors, drill a hole through both materials and drop the anchor into the hole. Once the lip is seated against the top of the material, hit the exposed pin with a hammer. The pin is driven down through the middle of the fastener pushing both sides out in a wedge fashion holding the fastener in place.

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Toggle Wing AnchorsToggle Wing Anchors

A Toggle Wing Anchor is used when a hollow wall is present. This is common when cinder blocks are used to create the walls of a building. They are also commonly used in drywall applications. It is not recommended to use heavy weight on these anchors especially in drywall as they will rip through the material.

To install one of these anchors, first a hole must be drilled big enough for the toggle portion of the anchor to push though. Once in the hollow part of the wall, the toggle wing will expand. Then using either a Phillips or Slotted head screwdriver, the bolt is driven into the toggle wing pulling it against the other side of the wall. This allows the bolt to tighten down on the material being hung.

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Double Expansion Shield AnchorDouble Expansion Shield Anchor

Double Expansion Shield Anchors are used primarily used in brick and block. As a screw is driven into the anchor, it starts to pull down towards the middle resulting in an expanded anchor. These anchors only expand so much. The reason for this is to prevent brick from cracking.

To install a double expansion shield anchor, simply drill a hole large enough for the anchor to drop into and then install the screw into the anchor. As you fasten the screw it will pull the bottom towards the middle and force the top down to the middle as well. The result it a limited but effective amount of expansion on the anchor. The limit of expansion highly reduces the chance of cracking brick or block.

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Sleeve AnchorsSleeve Anchors

Sleeve anchors are fairly simple to use and are primarily used in brick or block. They can be used in concrete but are not considered as strong as a wedge anchor. So, for light to medium holding applications, a sleeve anchor is a good choice. There are two common types of sleeve anchors. They are the Nut Drive which is commonly used for extra strength and Phillips/Slotted Combo Driven Flat Head which is used when a flush surface is required.

To install the nut driven style, drill a hole and place the sleeve anchor into the hole. Then place the washer and nut onto the exposed threading and begin fastening the nut. As the anchor is pulled up out of the concrete, the sleeve around it begins to expand wedging the anchor into place inside the hole. You can install the Combo Flat head style in much the same way except you are using a Phillips drive and the installation will leave the top flush with the surface of the installation material.

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Wedge AnchorsWedge Anchors

Wedge Anchors are extremely popular and are one of the strongest anchors for hold strength. Wedge anchors look and function like a sleeve anchor but have a much smaller sleeve near the bottom of the anchor.

To install a wedge anchor simply drill a hole that is the same size diameter as the anchor and place it into the hole. After placing the material being held to the concrete on the exposed portion, place the washer and thread the fastener onto the anchor. As the nut is tightened against the washer, it will begin pulling the anchor up. This will result in the wedge skirt catching the concrete and expanding and digging into the concrete as the anchor is pulled.

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