5/16-18 UNC 2A Thread Dimensions
Overview
The 5/16-18 UNC 2A thread is a type of screw thread commonly used in various engineering and mechanical applications. UNC stands for Unified National Coarse, which refers to the thread series. The "2A" designation indicates that the thread is a Class 2A thread, which has a specific tolerance and dimension range.
Thread Dimensions
The following are the dimensions for a 5/16-18 UNC 2A thread:
Major Diameter:
- Maximum: 0.3125 inches (7.94 mm)
- Minimum: 0.3085 inches (7.84 mm)
Pitch:
- 18 threads per inch (1.411 mm thread pitch)
Minor Diameter:
- Maximum: 0.2663 inches (6.77 mm)
- Minimum: 0.2591 inches (6.58 mm)
Thread Length:
- Varies depending on the application and specific requirements
Thread Engagement:
- The minimum thread engagement is typically 5-7 threads
Tolerances
The tolerances for a 5/16-18 UNC 2A thread are as follows:
Major Diameter:
- +0.0005 inches (-0.013 mm) to -0.0015 inches (-0.038 mm)
Pitch:
- ±0.0015 inches (±0.038 mm)
Minor Diameter:
- +0.0015 inches (+0.038 mm) to -0.0005 inches (-0.013 mm)
Applications
The 5/16-18 UNC 2A thread is commonly used in various applications, including:
- Automotive: Engine mounts, suspension components, and other assemblies
- Aerospace: Structural components, fasteners, and other assemblies
- Industrial: Pump and valve components, gearboxes, and other machinery
- Construction: Bolts and nuts for building structures and equipment
Conclusion
The 5/16-18 UNC 2A thread is a widely used thread size in various industries. Understanding the dimensions, tolerances, and applications of this thread is crucial for ensuring the proper design and assembly of components. By following the specifications outlined in this article, engineers and designers can ensure that their designs meet the required standards and perform optimally.
