Holo-Krome 72140 5/16"-18 x 2-1/2" Alloy Steel Socket Head Cap Screw (Pack of 100)

The Holo-Krome 72140 is a 5/16"-18 UNC x 2-1/2" socket head cap screw sold in a convenient pack of 100. Made from heat-treated alloy steel, these precision fasteners deliver superior tensile strength compared to equivalent hex head cap screws while requiring less surface area to counterbore — making them ideal for precision assemblies and well-tooled applications.

Holo-Krome socket head cap screws are engineered to exacting standards and conform to ASME B18.3 with a Unified Class 3A thread fit. Each screw features a Holo-Code lot traceability number stamped on the socket head, allowing full tracking without relying on the original packaging.

Key Features:

• Thread Size: 5/16"-18 UNC (coarse thread)
• Length Under Head: 2-1/2"
• Material: Heat-treated alloy steel with black oxide finish
• Thread Fit: Unified Class 3A (UNRC)
• Standard: Meets ASME B18.3
• Drive Type: Internal hex (Allen/hex key)
• Pack Quantity: 100 pieces
• Thermo-Forging®: Preserves continuous, uncut metal fibers for 15–20% increased fatigue resistance
• Precision Threads: Smooth, burnished threads for uniformity and accuracy
• Dimensional Control: Carefully engineered under-head bearing surface, radius, and thread profile
• Holo-Code Traceability: Lot number stamped on each socket head for quality tracking

Holo-Krome socket head cap screws are a trusted choice for industrial, manufacturing, and mechanical applications where high clamping strength, close tolerances, and a clean, professional appearance are required. The internal hex socket drive provides non-slip wrenching action, eliminating the risk of tool slippage and potential workpiece damage.