.250-20 UNC-2B: Understanding the Specifications
The .250-20 UNC-2B refers to a specific type of screw thread, commonly used in various industries, including aerospace, automotive, and construction. In this article, we will delve into the meaning and significance of each part of this specification.
.250: The Major Diameter
The ".250" in the specification refers to the major diameter of the screw thread, which is measured in inches. In this case, the major diameter is 0.250 inches or 6.35 mm. The major diameter is the largest diameter of the screw thread, measured from the crest of one thread to the crest of another thread.
20: The Threads per Inch
The "20" in the specification indicates the number of threads per inch (TPI). This means that the screw thread has 20 threads per inch, which is a relatively coarse thread. The threads per inch determine the pitch of the thread, which is the distance between two consecutive threads.
UNC: The Thread Form
"UNC" stands for Unified National Coarse, which is a thread form standard. The UNC thread form is a widely used standard in the United States and Canada. It is characterized by a coarse thread pitch, which makes it suitable for applications where high torque and resistance to stripping are required.
2B: The Thread Class
The "2B" in the specification refers to the thread class, which determines the tolerance and precision of the thread. The thread class is a measure of the thread's precision, with higher numbers indicating a tighter tolerance. In this case, the 2B thread class indicates a medium-high precision thread.
Applications and Industries
The .250-20 UNC-2B screw thread is commonly used in various industries, including:
- Aerospace: The coarse thread and high torque resistance make it suitable for aerospace applications where high-strength fastening is required.
- Automotive: The thread is used in automotive applications, such as engine mounts, suspension components, and steering systems.
- Construction: The thread is used in construction applications, such as in structural fasteners, anchor bolts, and foundation anchors.
Conclusion
In conclusion, the .250-20 UNC-2B screw thread is a specific type of thread that is widely used in various industries. Understanding the meaning and significance of each part of the specification is essential to ensure proper selection and use of the thread in different applications.
