.250-28 UNJF-3A Pitch Diameter: Understanding the Specifications
Overview
The .250-28 UNJF-3A pitch diameter is a specific type of thread specification used in fastening systems. It is commonly used in aerospace and defense industries, where high-strength and high-reliability fasteners are crucial. In this article, we will delve into the details of the .250-28 UNJF-3A pitch diameter and its specifications.
Thread Specifications
The .250-28 UNJF-3A pitch diameter is a type of Unified National Fine (UNF) thread, which is a widely used thread standard in the United States. The thread specifications are as follows:
- Major Diameter: .250 inches (6.35 mm)
- Threads per Inch (TPI): 28
- Pitch Diameter: .2285 inches (5.80 mm)
- Thread Form: UNJF (Unified National Joint)
- Class: 3A (high-strength, high-reliability)
Pitch Diameter Explanation
The pitch diameter is an essential aspect of thread specifications. It is the diameter of an imaginary coast that intersects the thread crests at a point midway between the major and minor diameters. In the case of the .250-28 UNJF-3A pitch diameter, the pitch diameter is .2285 inches (5.80 mm).
The pitch diameter is critical because it affects the thread's strength, compatibility, and assembly process. A smaller pitch diameter can lead to a stronger thread, but it may also make assembly more challenging. Conversely, a larger pitch diameter can make assembly easier, but it may compromise the thread's strength.
Applications
The .250-28 UNJF-3A pitch diameter is commonly used in high-strength, high-reliability applications, such as:
- Aerospace: Used in aircraft and spacecraft structures, where high-strength and low-maintenance fasteners are essential.
- Defense: Used in military equipment, such as weapons systems, vehicle structures, and communication devices.
- High-Performance: Used in high-performance industries, such as motorsports, racing, and high-speed machinery.
Conclusion
In conclusion, the .250-28 UNJF-3A pitch diameter is a specific thread specification used in high-strength, high-reliability applications. Its unique combination of major diameter, threads per inch, and pitch diameter makes it an ideal choice for industries that require exceptional fastening performance. By understanding the specifications and applications of the .250-28 UNJF-3A pitch diameter, engineers and designers can make informed decisions when selecting fasteners for their projects.
