UNC Bolts Specification (ANSI B18.2.1 / A4) Made from Grade 316 Stainless Steel
Unified National Coarse (UNC) bolts conforming to ANSI B18.2.1 and made from grade 316 stainless steel (A4) are widely used for their excellent corrosion resistance and high strength. Grade 316 stainless steel contains molybdenum, which significantly enhances its resistance to corrosion, particularly in chloride and marine environments.
General Specifications:
Material: Grade 316 Stainless Steel (A4)
Corrosion Resistance: High resistance to pitting and crevice corrosion, particularly effective in marine and chloride-rich environments.
Mechanical Properties: High tensile strength and toughness.
Thread Standard: Unified National Coarse (UNC)
Thread Angle: 60 degrees
Thread Profile: Coarse threads provide better tolerance to thread damage and ease of assembly in softer materials.
Spanner (Wrench) Sizes for UNC Bolts:
The table below lists the appropriate spanner sizes for commonly used UNC bolts.
Bolt Size (UNC)
Threads Per Inch (TPI)
Across Flats (Spanner Size)
Across Corners
1/4-20 UNC
20
7/16" (11.11 mm)
0.505" (12.83 mm)
5/16-18 UNC
18
1/2" (12.70 mm)
0.577" (14.65 mm)
3/8-16 UNC
16
9/16" (14.29 mm)
0.650" (16.51 mm)
7/16-14 UNC
14
5/8" (15.88 mm)
0.794" (20.17 mm)
1/2-13 UNC
13
3/4" (19.05 mm)
0.866" (21.99 mm)
5/8-11 UNC
11
15/16" (23.81 mm)
1.150" (29.21 mm)
3/4-10 UNC
10
1-1/8" (28.58 mm)
1.299" (32.99 mm)
7/8-9 UNC
9
1-5/16" (33.34 mm)
1.505" (38.23 mm)
1-8 UNC
8
1-1/2" (38.10 mm)
1.732" (43.99 mm)
Detailed Description:
1/4-20 UNC:
Spanner Size: 7/16" (11.11 mm)
Applications: Light machinery, electronics, and household applications where corrosion resistance is critical.
Applications: Structural joints, motor mounts. Commonly used in building and construction, providing strong and reliable connections.
7/16-14 UNC:
Spanner Size: 5/8" (15.88 mm)
Applications: Heavy machinery, construction equipment. Ideal for applications requiring higher strength and load-bearing capacity with corrosion resistance.
1/2-13 UNC:
Spanner Size: 3/4" (19.05 mm)
Applications: Automotive frames, industrial machinery. Widely used in various industrial applications for securing parts and components in corrosive environments.
5/8-11 UNC:
Spanner Size: 15/16" (23.81 mm)
Applications: Bridge construction, large machinery. Provides high strength for heavy-duty applications requiring durability and resistance to harsh environments.
3/4-10 UNC:
Spanner Size: 1-1/8" (28.58 mm)
Applications: Heavy equipment, structural applications. Ensures stability and strength in heavy construction and industrial setups with the added benefit of corrosion resistance.
7/8-9 UNC:
Spanner Size: 1-5/16" (33.34 mm)
Applications: High-load applications, infrastructure projects. Suitable for high-stress applications where durability and corrosion resistance are critical.
1-8 UNC:
Spanner Size: 1-1/2" (38.10 mm)
Applications: Industrial installations, large-scale construction. Used in major structural applications due to its high load-bearing capacity and resistance to corrosion.
Summary
UNC bolts made from grade 316 stainless steel (A4) offer exceptional strength and corrosion resistance, making them ideal for a variety of industrial and marine applications. The specified spanner sizes ensure proper fit and torque application, facilitating efficient and secure assembly. These bolts are preferred for their reliability and performance in harsh environments, providing long-lasting durability and safety.
UNC Bolts Specification (ANSI B18.2.1 / A4) Made from Grade 316 Stainless Steel
Unified National Coarse (UNC) bolts conforming to ANSI B18.2.1 and made from grade 316 stainless steel (A4) are widely used for their excellent corrosion resistance and high strength. Grade 316 stainless steel contains molybdenum, which significantly enhances its resistance to corrosion, particularly in chloride and marine environments.
General Specifications:
Material: Grade 316 Stainless Steel (A4)
Corrosion Resistance: High resistance to pitting and crevice corrosion, particularly effective in marine and chloride-rich environments.
Mechanical Properties: High tensile strength and toughness.
Thread Standard: Unified National Coarse (UNC)
Thread Angle: 60 degrees
Thread Profile: Coarse threads provide better tolerance to thread damage and ease of assembly in softer materials.
Spanner (Wrench) Sizes for UNC Bolts:
The table below lists the appropriate spanner sizes for commonly used UNC bolts.
Bolt Size (UNC)
Threads Per Inch (TPI)
Across Flats (Spanner Size)
Across Corners
1/4-20 UNC
20
7/16" (11.11 mm)
0.505" (12.83 mm)
5/16-18 UNC
18
1/2" (12.70 mm)
0.577" (14.65 mm)
3/8-16 UNC
16
9/16" (14.29 mm)
0.650" (16.51 mm)
7/16-14 UNC
14
5/8" (15.88 mm)
0.794" (20.17 mm)
1/2-13 UNC
13
3/4" (19.05 mm)
0.866" (21.99 mm)
5/8-11 UNC
11
15/16" (23.81 mm)
1.150" (29.21 mm)
3/4-10 UNC
10
1-1/8" (28.58 mm)
1.299" (32.99 mm)
7/8-9 UNC
9
1-5/16" (33.34 mm)
1.505" (38.23 mm)
1-8 UNC
8
1-1/2" (38.10 mm)
1.732" (43.99 mm)
Detailed Description:
1/4-20 UNC:
Spanner Size: 7/16" (11.11 mm)
Applications: Light machinery, electronics, and household applications where corrosion resistance is critical.
Applications: Structural joints, motor mounts. Commonly used in building and construction, providing strong and reliable connections.
7/16-14 UNC:
Spanner Size: 5/8" (15.88 mm)
Applications: Heavy machinery, construction equipment. Ideal for applications requiring higher strength and load-bearing capacity with corrosion resistance.
1/2-13 UNC:
Spanner Size: 3/4" (19.05 mm)
Applications: Automotive frames, industrial machinery. Widely used in various industrial applications for securing parts and components in corrosive environments.
5/8-11 UNC:
Spanner Size: 15/16" (23.81 mm)
Applications: Bridge construction, large machinery. Provides high strength for heavy-duty applications requiring durability and resistance to harsh environments.
3/4-10 UNC:
Spanner Size: 1-1/8" (28.58 mm)
Applications: Heavy equipment, structural applications. Ensures stability and strength in heavy construction and industrial setups with the added benefit of corrosion resistance.
7/8-9 UNC:
Spanner Size: 1-5/16" (33.34 mm)
Applications: High-load applications, infrastructure projects. Suitable for high-stress applications where durability and corrosion resistance are critical.
1-8 UNC:
Spanner Size: 1-1/2" (38.10 mm)
Applications: Industrial installations, large-scale construction. Used in major structural applications due to its high load-bearing capacity and resistance to corrosion.
Summary
UNC bolts made from grade 316 stainless steel (A4) offer exceptional strength and corrosion resistance, making them ideal for a variety of industrial and marine applications. The specified spanner sizes ensure proper fit and torque application, facilitating efficient and secure assembly. These bolts are preferred for their reliability and performance in harsh environments, providing long-lasting durability and safety.
