1/2-13 x 5-1/2" Socket Head Cap Screws Bolts, 12.9 Grade Alloy Steel, Black Oxide Finish, Allen Hex Drive, Full Thread, 4-Pack

• Key Specs: 1/2-13 x 5-1/2"; Head Diameter: 0.725" – 0.75" (18.4 – 19 mm); Head Height: 0.5" (12.7 mm); Drive Size: 3/8" Allen Hex; Thread: Partial; Package: 4 PCS
• Engineered from high-tensile 12.9 grade alloy steel, this bolt offers the ultimate in mechanical strength and load-bearing capacity. The added black oxide finish provides a basic layer of corrosion resistance and a clean, non-reflective appearance suitable for most industrial environments
• The knurled (grip) pattern around the head allows for easy finger-tightening and tool grip in oily or gloved conditions. The internal hex drive enables high-torque installation with superior force transfer and minimal risk of stripping or cam-out
• This large-diameter, high-strength fastener is engineered for the most demanding applications, such as structural steel connections, heavy machinery baseplates, large hydraulic press assemblies, and mining or forestry equipment frames
• The unthreaded shoulder (grip length) is designed to act as a precise dowel, providing accurate alignment and minimizing side movement in clearance holes. This design concentrates clamping force directly under the head, maximizes shear strength, and significantly reduces the risk of thread fatigue and fretting in high-vibration applications, such as machinery links and dynamic structural joints

Elevate your critical assemblies with our professional-grade 12.9 Alloy Steel Knurled Socket Head Cap Screws Unmatched Strength: 12.9 Alloy Steel vs. 304 Stainless Steel Choose 12.9 for ultimate mechanical performance; choose 304 for superior corrosion resistance in harsh environments. A basic black oxide finish provides a layer of protection and a clean appearance for typical industrial use Optimized Thread Design: Full Thread vs. Partial Thread Our series offers both Full Thread and Partial Thread options to match your specific engineering needs. Full Thread Screws are versatile for general use, ideal for through-hole applications, joining thick materials, or when used with a nut, providing maximum thread engagement along the entire length. Partial Thread Screws feature a precise unthreaded shoulder (grip length). This design acts like a dowel, ensuring perfect alignment, maximizing shear strength, and concentrating clamping force directly under the head—making them the preferred choice for precision-machined parts, dynamic joints, and high-vibration applications.