1/4" UNC Stainless Steel Grade 316 Hex Head Bolts, made to DIN 931 standards, are high-quality fasteners designed for robust applications requiring exceptional corrosion resistance and strength. These bolts are used extensively in marine, chemical, and outdoor applications due to the superior properties of 316 stainless steel. In Australia

Characteristics

1. Material:
   • Grade 316 Stainless Steel: Known for its excellent corrosion resistance, especially against chlorides and acidic environments, making it ideal for marine and chemical applications.
2. Thread Type:
   • UNC (Unified National Coarse): The thread pitch for 1/4" UNC bolts is 20 threads per inch (TPI), providing a coarser thread that is less likely to strip and allows for quick assembly and disassembly.
3. Standards:
   • DIN 931: Specifies the dimensions and mechanical properties for partially threaded hex bolts.

Dimensions and Spanner Size

Below are the dimensions and a simple drawing of a 1/4" UNC hex head bolt made to DIN 931:

1. Diameter: 1/4 inch (6.35 mm)
2. Thread Pitch: 20 TPI (threads per inch)
3. Hex Head Dimensions:
   • Across Flats (AF): 7/16 inch (11.11 mm)
   • Across Corners (AC): 0.505 inch (12.83 mm)
   • Head Height (k): 0.163 inch (4.14 mm)
4. Spanner Size: 7/16 inch (11.11 mm)
5. Shank Length: Variable depending on the bolt length, with a partially threaded portion.
6. Thread Length: For bolts up to 125 mm in length, thread length = 2 x diameter + 6 mm. For bolts longer than 125 mm, thread length = 2 x diameter + 12 mm.

Applications

1. Marine Applications:
   • Ideal for boat building, docks, and other applications exposed to saltwater.
2. Chemical Processing:
   • Used in environments where exposure to corrosive chemicals is common.
3. Construction:
   • Suitable for outdoor structures, bridges, and buildings in coastal areas.
4. Automotive and Aerospace:
   • Used in areas exposed to harsh environmental conditions.

Benefits

• Corrosion Resistance: Grade 316 stainless steel offers superior resistance to corrosion and oxidation, even in harsh environments.
• Strength: Provides robust performance under high-stress conditions.
• Durability: Long-lasting with minimal maintenance required, ideal for long-term applications.

Installation Tips

• Spanner/Wrench Size: Use a 7/16 inch spanner or wrench to tighten the hex head bolt.
• Pre-Drilling: If used in wood or other soft materials, pre-drilling a pilot hole can help prevent splitting and ensure a secure fit.
• Torque Specifications: Follow appropriate torque specifications to avoid over-tightening, which could damage the bolt or the material being fastened.

Conclusion

1/4" UNC stainless steel grade 316 hex head bolts made to DIN 931 are essential components for applications requiring high durability and corrosion resistance. Their robust construction and adherence to DIN 931 standards ensure reliability and consistency in demanding environments. Whether for marine, chemical, or outdoor use, these bolts provide a secure and long-lasting solution for a variety of construction and industrial needs.