55 Roscas Npt Tabla Pdf

Tabela de Identificação de Roscas.pdf
Tabela de Identificação de Roscas.pdf from pt.scribd.com



Roscas NPT, also known as National Pipe Taper threads, are widely used in the plumbing industry for joining pipes and fittings. These threads have a unique design that allows for a tight seal and easy assembly. In this article, we will explore the NPT thread specifications and provide a comprehensive NPT thread table in PDF format.

Understanding NPT Threads

NPT threads are tapered, meaning they have a gradual decrease in diameter along the length of the thread. This tapering allows for a tight seal when the male and female threads are joined together. The threads are used in a variety of applications, including water and air systems, hydraulic systems, and gas lines.

NPT Thread Specifications

Before we dive into the NPT thread table, let's take a look at the specifications of NPT threads:

1. Thread Angle:

NPT threads have a thread angle of 60 degrees. This means that each thread makes a 60-degree angle with the centerline of the pipe.

2. Thread Pitch:

The thread pitch of NPT threads is measured in threads per inch (TPI). The most common thread pitches for NPT threads are 18 TPI and 27 TPI.

3. Thread Crest and Root:

The crest of an NPT thread is the topmost point of the thread, while the root is the bottommost point. The crest and root of NPT threads are rounded, which helps in achieving a tight seal.

4. Thread Engagement:

For proper engagement, NPT threads require a minimum of five threads to be fully engaged. This ensures a secure connection and prevents leakage.

5. Sealing Method:

NPT threads rely on the interference between the male and female threads to create a seal. This interference, combined with the taper, helps in preventing leaks.

NPT Thread Table in PDF Format

Below is a comprehensive NPT thread table in PDF format that provides all the necessary information for selecting the right NPT thread size:

[Embed the PDF file here]

Using the NPT Thread Table

The NPT thread table provides information on various parameters such as thread size, pitch, and engagement length. Here's how you can use the table:

1. Determine the Required Thread Size:

Measure the outer diameter of the male thread or the inner diameter of the female thread. Cross-reference this measurement with the thread sizes listed in the table to find the corresponding NPT thread size.

2. Determine the Thread Pitch:

Identify the thread pitch required for your application. The NPT thread table provides information on both 18 TPI and 27 TPI thread pitches.

3. Determine the Engagement Length:

The NPT thread table also lists the recommended engagement length for each thread size and pitch. Ensure that the threads are fully engaged to achieve a proper seal.

4. Select the Right Fitting:

Once you have determined the NPT thread size, pitch, and engagement length, you can select the appropriate fitting for your application. Ensure that the fitting has compatible NPT threads.


Roscas NPT are widely used in plumbing applications due to their tight sealing capabilities. Understanding the NPT thread specifications and using the NPT thread table can help you select the right thread size, pitch, and engagement length for your plumbing needs. Ensure proper assembly and engagement to achieve a reliable and leak-free connection.

Disclaimer: The NPT thread table provided in this article is for informational purposes only. Always refer to official standards and consult with professionals for accurate and up-to-date information.