Do you know that every gear mechanism contains a snap ring? If not, there’s nothing to blame yourself about. Yes, it is an important part of any mechanism because it is responsible for holding the assembly properly inside shafts and bore housings.
All machines have snap rings in them. If they have any mechanical application, if you open and detach all parts, you will definitely find snap rings inside the shaft.
But what exactly are these snap rings and how do you measure them? The question of measurement comes about because each machine that has a different size, contains small parts that are of different sizes.
So, something that holds the assembly together is bound to go through a lot of strain. It might need to be changed more often than other parts of a mechanism because it may hold an assembly together but is not that thick a part.
That’s why knowing proper measurements is important. Before jumping into the measurements part, let’s find out what snap rings actually are.
What are Snap Rings?
A snap ring AKA a C-clip is a metallic ring that looks like a C. The main purpose of a snap ring is to work as a retaining fastener. It sits inside or outside a shaft depending on the type of the ring and retain the components of an assembly.
The retaining mechanism has given it the name of retaining ring. Another por pose of this ring is to work as a shoulder to secure the assembly inside the bore housing or a shaft. A small part of the circumference of the ring sticks out from the groove.
Types of Snap Rings
Universally there are two types of snap rings. They are–
- Internal Snap rings
- External Snap rings
Despite what the name suggests, both the rings look almost identical. Let’s discuss their differences.
External Snap Rings
External rings are wrapped around the shaft so that it can retain the shaft assemblies. The installation process of an external ring is also different than the other one.
The ring to install or to be removed from a bore housing or a shaft requires expansion. You have to expand the snap ring using pliers.
Internal Snap Rings
Internal snap are the exact opposites of external ones. They are housed inside a shaft or a bore housing in order to keep the components to the assembly from coming out from the bore housing or the shaft.
While the external ring retains the assembly from the inside, the internal ring keeps the assembly line from coming outside. This action depends on what type of mechanism is installed in the bore housing.
Apart from these two types, there are some other types of snap rings available in the market. These are signified according to their designs. If you want, you can classify them in the external-internal category too. They are–
- Circlip without grip holes
- Circlip with grip holes
- Constant section snap ring
- Tapered section snap ring
- Spiral lock snap ring
Difference between Measurement
In order to measure any snap ring, you first have to know whether it’s an internal one or an external one. Because the measuring technique depend on which circumference is in use.
In the case of external snap rings, the internal circumference is used and in the case of internal snap rings, the external circumference plays a role. So, while measuring the type of snap ring, you need to measure the circumference according to the utility.
How to Measure Snap Rings
There are two types of measurement that anyone has to make on snap rings. One being the circumference, and second one being the thickness.
The measuring part is easy. All you need is a Digital Slide / Vernier calipers. Now what exactly is a Vernier Calipers?
A vernier Calipers is a ruler like object which has tactically designed and placed jaws with which you can measure the circumference and width of any device very easily. The digital meter delivers the accurate result up to 2 decimal points below zero.
Measuring Internal Snap Ring
Now, to measure an internal snap ring, let’s follow the steps below–
At first Slide the external jaws open. As you open the jaws, create enough space in between so that you can place the snap ring inside the jaws.
Now, place the ring and close the jaws to secure the ring inside. The vernier calipers digital meter will show you results.
Here’s is an issue. As the snap ring is strong but not a thick object, for installation purposes it is designed so that it can be expanded or squeezed. So, if you tighten the jaws too much, the caliper might give you a faulty result. That’s why, place the jaws firmly, but don’t pressurize the structure.
Measuring External Snap Rings
In the case of external snap rings, the internal circumference is what we will measure. To do that, there are a pair of jaws on the upper side the caliper. They are called the internal jaws.
Following the same method as before expand the jaws. But this time, make sure you expand them just so that they can fit inside the circumference of the external ring.
Now, place the ring and tighten the jaws inside the circumference. Again, external rings are designed so that they can be expanded while installation and removal.
So, don’t put too much pressure, just make sure the setting is firm.
Measuring the Thickness
To measure the thickness, there is no difference between the process in case of external and internal snap rings. All you have to do is place the ring body inside the external jaws and tighten firmly. You will get accurate readings on the caliper.
Also Read: Best Hog Ring Pliers Kits
So, this is how you can measure snap rings. The process is pretty easy if you know how to measure snap rings depending on their utility.
Follow both methods properly. You will be able to measure snap rings without breaking a sweat.