The Ultimate Guide to Pipe Nipple Measurements: Everything You Need to Know for Your Piping System

What are pipe nipples, and why do they matter? Pipe nipples are short pieces of pipe with male threads on either one or both ends used to join female-threaded pipes or fittings. They are commonly used in household and industrial applications like water, oil, gas, and electricity. 

However, pipe nipples are not as simple as they seem. They have different types, materials, and sizes, each with its own characteristics and functions. Measuring pipe nipples correctly is vital for ensuring a secure connection, a leak-free system, and a high-performance operation. In this blog article, we will teach you how to measure pipe nipples accurately, what aspects to pay attention to, and what errors to avoid.

Understanding Pipe Nipples

A pipe nipple is a type of pipe fitting commonly used to connect two female threaded pipes or fittings. It is a short piece of pipe with male threads on both ends, created by cutting a certain length of pipe. The nipple is versatile and can be used for low-pressure discharge and suction of various compatible liquids, but it is not recommended for compressible products like air, nitrogen, or steam.

Pipe nipples are available in a vast array of wall thicknesses and materials. The choice of a pipe nipple is influenced by factors such as the size and structure of the pipe, the type and number of clamps used, clamp installation and placement, temperature, and the product being transported.

13 types of pipe nipples

Barrel Nipples: These have threads on both ends and a bare pipe in between. These pipe nipples offer improved strength, faster connection speed, and low labour intensity. The specified length can be determined by the total measurement of the bare pipe and its TBEs.

Seamless Pipe Nipple: Similar to a barrel nipple, it has threads on both ends but lacks a welded seam. It provides a strong connection for pneumatic fittings and is suitable for high-pressure plumbing applications.

Close Nipple: Also known as the running nipple, it lacks a bare pipe between the threaded ends. When each female fitting is screwed tightly per end, little to none of the nipple is exposed. However, installing it can be challenging and may require a specialty tool called the internal pipe wrench or nipple wrench.

Shoulder Pipe Nipples: These have a narrow, unthreaded area that can't accommodate a pipe wrench. When the two female fittings are screwed at each end, only a small surface area is exposed. They are often varnished to prevent corrosion and are suitable for air or gas applications.

Right-Left Hand Pipe Nipple: This nipple has a right-hand thread on one end and a left-hand thread on the other. It's primarily used in gas pipes or applications where unions are not allowed.

Hexagonal Nipple: Also known as the hex nipple, it has a middle hexagonal section similar to a nut. This allows a normal wrench to hold it securely. If the threads of the nipples are farther apart, it's considered a long hexagonal nipple. It's best used in plumbing, automotive, and industrial applications.

Reducing Or Unequal Nipple: This nipple's threaded connection varies. One end requires a larger connection, while the other can only be attached to a smaller one. This leads to a greater flow rate of fluids in the smaller pipe. The reducer nipple may or may not have a hexagonal middle.

Swage Nipples: These are used to connect a combination of pipe nipples and can transport fluids from one female fitting to another due to their changing diameter. They come in two forms, vertical and horizontal pipelines, and their ends may be plain, threaded, or bevelled.

TOE Pipe Nipple: Standing for 'threaded one end', this nipple has an unthreaded end that is either plain or bevelled. It's manufactured through standard compression coupling and is commonly used in oil tank legs.

Hose Nipple: This nipple has a male fitting on one side and a hose barb on the other. It can transport drinking water but only withstand a pressure rating of 100 psi.

Weld Pipe Nipple: Unlike others, this nipple has no threads on its end connections and can only be fitted through welding. It offers good sealing, reliability, and resistance, making it suitable for applications with vibration and changes in temperature/pressure.

Grooved Pipe Nipple: Used in various industrial applications, this nipple comes in three configurations: Groove x Groove, Groove x Bevel, and Groove x MPT. It's available in multiple dimensions and is interchangeable.

King Pipe Nipple: Also known as a combination nipple, this type allows the transition from hose pipes to threads. It's often made with plated steel for rust resistance. It comes with a male pipe thread and can be installed directly. However, its applications are limited, and it's not recommended for transporting compressible products such as air or steam.

The Importance of Accurate Measurements

The accurate measurement of pipe nipples is crucial for successful plumbing. Here are several reasons why precise measurement is so important:

Seal and Leak Prevention: Accurate measurements ensure a tight seal, preventing leaks that could lead to damage or environmental hazards.

Pressure Integrity: Proper measurements ensure pipe nipples can withstand intended pressures, avoiding structural weaknesses and potential ruptures.

Flow Efficiency: Precise measurements maintain efficient fluid flow, preventing restrictions, pressure drops, and energy inefficiencies.

Material Compatibility: Accurate sizing ensures that the chosen materials are compatible, preventing corrosion, degradation, and contamination.

Regulatory Compliance: Adherence to industry standards and regulations is crucial for safety and compliance with established codes.

How are Pipe Nipples Measured?

When choosing a pipe nipple, it's crucial to consider several vital specifications, such as inner or outer diameter, length, material, and end connection. But how do you measure the length of a pipe nipple? 

The overall length of a pipe nipple is measured from one end to the other, regardless of whether it's plain or threaded. You can use a calliper or a combination of a thread and tape measure to get an accurate measurement. 

Once the pipe or fitting is attached to the nipple, the length is established by subtracting the thread engagement from both ends. The thread engagement is the length of the pipe inserted into the nipple to create a secure seal. If the female threaded fittings are closely situated, and the nipple is concealed, the close length is computed as twice the thread engagement. 

To determine the precise length of the nipple in inches, you can refer to a nominal diameter conversion chart. This allows you to adhere to the specified dimensions for a seamless fit and optimal performance in your piping system.

How are Pipe Nipples Measured?

Determining Pipe Size

Aside from measuring the pipe nipple size, it's also essential to know how to gauge pipe size. The process is simple - for pipes with male threads, focus on the outside diameter, and those with female threads, concentrate on the inner diameter.

To measure the pipe size for pipes or fittings with male threads, follow these steps:

  1. Wrap a thin string around the pipe. 
  2. Mark the point where the string meets the pipe using a marker pen. 
  3. Measure the string from the tip to the marked point with a tape measure or ruler to determine the pipe's circumference. 
  4. Calculate the diameter by dividing the circumference by 3.14.
  5. Use the nominal diameter conversion chart to translate the diameter readings into the correct nominal diameter representing the true pipe size.

For female threaded pipes, follow these steps:

  1. Place a tape measure or ruler at the pipe's opening to measure the inside diameter. 
  2. Refer to the nominal diameter chart for pipe sizes to convert the inside diameter to the nominal diameter, revealing the actual size of the pipe.

By following these step-by-step instructions, you can confidently determine the size of your pipes and easily navigate the intricacies of your piping system.

How to determine accurate pipe size.

Common Mistakes in Measuring Pipe Nipples

Accurately measuring pipe nipples is crucial for ensuring a piping system's proper functioning and integrity. However, there are several common mistakes that people often make when measuring pipe nipples, which can lead to issues like leaks, poor fittings, and overall system inefficiencies. Here are some of the most common mistakes to avoid:

- Using the wrong units of measurement can lead to significant errors. Ensure that the units specified for the pipe dimensions (e.g., inches, millimetres) are consistent with your measurements.

- Neglecting thread engagement, the portion of the pipe covered by threads, can result in inaccurate measurements. When measuring the length of a threaded pipe nipple, make sure to account for thread engagement.

- Misreading a tape measure or ruler can lead to inaccurate measurements. Take extra care to read the measurement accurately, especially when dealing with small increments.

- Ignoring the material thickness of the pipe nipple can affect the accuracy of measurements, particularly when determining inner or outer diameters. Measure from the outer surface of the material.

- Failing to identify and account for the specific thread type (e.g., NPT, BSP) can result in improper fittings and inaccurate measurements.

- Using measuring tools that are not correctly calibrated can lead to inaccuracies. Regularly check and calibrate tools such as callipers and tape measures to ensure precision.

- Neglecting to consider the compatibility of the material with the substances being transported can lead to corrosion, degradation, or contamination.

- Neglecting to convert measured diameters to nominal diameters using the appropriate conversion chart can result in selecting the wrong pipe size, leading to improper fittings and connections.

- Relying solely on visual inspection may not provide accurate measurements. Always use appropriate measuring tools for precise and reliable results.

- Failing to consider the overall pipe configuration for complex piping systems with various bends and angles can result in inaccurate measurements. Account for the entire pipe layout for a comprehensive assessment.

By avoiding these common mistakes and following proper measurement procedures, you can ensure accurate and reliable dimensions for pipe nipples in your piping system.


Pipe nipples are essential components of any piping system, and measuring them correctly is crucial for ensuring a tight seal, efficient flow, and material compatibility. We hope this article has given you a comprehensive overview of the different types of pipe nipples, their roles, and how to measure them correctly. If you enjoyed this article, share it on social media and spread the knowledge.

Product Recommendations: 

Prochem Hex Nipple Stainless Steel Fitting 316 R40 40NPT 17009
Conduit Screwed Nipple 32mm Grey Set of 2
Nipple BSP 1" 316 Stainless Steel
Clipsal Steel Couplings Cable Management Machined Brass 20mm Brass Nipple 1243/20



Home, P. I. (2023, March 27). 13 different types of pipe nipples. Pip's Island Home.

Home, P. I. (2022, December 9). How to measure pipe nipple length? (5 types). Pip's Island Home.

Alloys, S. S. &. (2023, June 29). What Is A Pipe Nipple? - Surya Fittings Blog. Surya Fittings Blog.

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