What is the rod end thread pitch? What does it mean?

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Thread pitch is the distance between threads. It is a critical measurement for rod end bearings used in rod end joints to connect two parts. Thread pitch and rod end size determine the required rod bearing size and, thus, the joint strength.

This blog will discuss rod’s end thread pitches and how to measure them. We shall also cover the benefits of knowing the rod’s end thread pitch and how it can help you make an informed decision while buying rod end bearings.

What is the rod’s end thread pitch?

The thread pitch of a rod is the thread diameter divided by the diameter of the rod itself. Threads with a higher thread pitch are thinner and more durable than those with a low thread pitch. The end of the thread is coated in a layer of material called a ‘binder’ that helps it to slide easily on the rod’s surface. This binder prevents the thread from slipping off and breaking. The end of the thread often features a logo, name, or other identifying feature that serves as a point of reference for buyers and others without access to the rod’s specifications.

What are the Types of Thread Pitches?

There are three common thread pitches in the industry. They are UNC, UNF, and UNEF.

UNC is a standard screw thread with a larger diameter than fine threads. It is a general-purpose thread type that can be used on many applications.

The fine size of UNC threads allows them to be used on precision components without the risk of damaging the threading. On the other hand, the coarse size of UNC threads makes it easier to secure the fasteners in place during assembly.

The term ‘fine’ refers to the size of the individual threads. The fine size of threads allows them to be used in precision applications without any risk of damaging the threading. As for Unified Extra-Fine (UNEF), it’s a finer thread than Unified Fine (UNF). It’s used for precision parts as it has tighter tolerances and precise dimensions.

The pitch refers to how many threads are on the screw shaft. The term ‘pitch’ also refers to how far apart the individual threads are from one another. So, in essence, unified coarse (UNC) is a standard screw thread with a larger diameter than fine threads, whereas unified fine (UNF) is finer than UNC, and unified extra-fine (UNEF) is finer still than UNEF.

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How to Measure the Rod’s End Thread Pitch?

The thread pitch is the distance between the centers of two adjacent threads on a bolt, rod, or another threaded component. It is measured in millimeters or inches and describes the diameter of the thread’s outer edge.

The thread pitch is important in determining a threaded connection’s strength and durability. Different thread pitches provide different levels of protection, with larger thread pitches providing greater protection than smaller ones. In addition, choosing the right thread pitch can reduce potential damage to a component and improve its reliability.

To choose the right thread pitch, it’s vital to understand its significance and the different types of threads available. Choose the type of thread that best matches the application for enhanced performance and longevity.

For example, a high-quality stainless steel bolt with a standard-size hex head should have an NPT (National Pipe Thread) size fitting on its end. A hexagonal nut with an M8 thread should be used with an M8 screw, while an SAE Standard size locking washer should be used with an SAE Standard size nut. Also, it is vital to choose the correct measuring tool for accurate measurement and ensure consistency in terms of length and diameter.

Benefits and Uses of Knowing Rod’s End Thread Pitch

Awareness of the rod’s end thread pitch is essential while fastening components with threads. This length is important because it determines the size of the nut, bolt, or screw used to secure the part. It also helps determine torque settings when using nuts, bolts, and screws. Knowing the rod’s end thread pitch helps select accessories and tools for a project. These items are designed to be compatible with similar sizes of threading on the rod. Hence, knowing the rod’s end thread pitch can help you select the best accessories for your project.

In addition, knowing the rod’s end thread pitch can help you select the correct size of fasteners for a particular job. This length is based on an inch value included in the specifications of the accessory or tool being used. Thus, by taking time to read up on this length, you can determine which size of fastener will work best for your job.

Frequently Asked Questions

What are the most common thread pitches used for rods?

The most common thread pitches used for rods are 1/4”-20, 5/16”-18, and 3/8”-16. Thread pitch is the number of threads per inch (TPI) on a rod or bolt, meaning it refers to how far apart each thread is spaced along the length of the rod. Consequently, thread pitches can range from very fine to very coarse, depending on the application. For example, a rod used in a precision application may require a finer thread pitch than one used in a general application. Therefore, it is important to choose the right thread pitch according to the specific rod application to ensure that the rod provides the desired results.

What factors should I consider when selecting a thread pitch for my rod?

Selecting the right thread pitch for your rod is important and requires some consideration. Here are the main factors that you should consider when choosing the right thread pitch:

1. Strength of the material: The strength of the material that the rod is intended for should be considered when selecting a thread pitch. You will want to ensure that the rod can handle the pressure and weight you will place upon it without damage.

2. Match to screw/bolt size: The thread pitch should also match the size and type of screw or bolt you will use with it. If the thread pitch doesn’t line up properly with the screw/bolt size, it won’t fit correctly and could cause potential damage.

3. Compatibility with existing parts: Ensure that the thread pitch is compatible with any parts that need to be connected, such as washers, nuts, and other pieces. Otherwise, you may have difficulty connecting them later on.

4. Adequate surface area for adhesives: Remember to choose a thread pitch that provides adequate surface area if needed. This helps ensure a secure connection between the rod and whatever parts need to be connected to it.

Are there any safety considerations when using threaded rods?

Yes, there are certain safety considerations when using threaded rods. Here are a few of the most important ones:

1. Always use nuts or other secure fastening devices in conjunction with the threaded rod to ensure that everything is securely in place.

2. Make sure to use the correct size of nuts and washers for the job; this will also help to prevent over-tightening the nut, which could cause the rod to break or bend.

3. When working with threaded rods and other fasteners, it’s essential to wear appropriate safety goggles, gloves, and any other protective gear needed for the job. This will help protect your eyes from flying particles and your hands from splinters or sharp edges.

4. Finally, ensure that you follow the manufacturer’s instructions for installing and using the threaded rod to ensure safe operation.


Thread pitch is a vital measurement in the rod end design. It helps in the accurate machining and fitting of rod ends and the related parts in determining the performance and load-bearing capacity of the rod end bearings. This knowledge enables you to select the right rod end for your application and select rod end bearings for optimal functioning. Knowing the thread pitch gives you a competitive edge when it comes to comparing different rod end designs and selecting the most suitable one for your application.